# Greeks：把局部导数变成带单位的风险

把delta、gamma、vega、theta写成带单位的局部导数，用50点和500点完整重定价量化误差。

Entry: zh-m19 | Node: M19 | Language: zh | Editorial revision: 2026-09-21

## Teaching instructions
你正在教M19《Greeks：把局部导数变成带单位的风险》，内容版本2026-09-21-MEFG-review-v3。读者已有高年级本科至研究生的数学基础。

先确认选用本篇共同正文和哪些分支，再实际读取agent_packet列出的当前必读完整原文。PDF需读脚注、表图与符号；只拿到摘要/目录/搜索片段不算完成。记录实际版本、范围与内容对应，不沿用编辑端“已读”充当本次读取；同会话已完整取得相同版本单元可以复用。若所需单元失败，尝试机构正式等价全文；仍缺失则指出具体单元，不凭记忆补成已读教学。runtime_reading_log从空开始。

独立学习任务：给定单位及固定条件，计算一阶/部分二阶近似，并用完整定价指出小变动和大变动误差。
专属诊断与正向讲解：用50点后用500点，要求先判断vega是每一个百分点还是sigma=1，再将点数乘100。最后解释delta .556803与N(d2) .510441不同。
反馈尺度：输入多个变量变化时不声称只加spot gamma已经包含所有二阶项；期权点、美元和概率不混。

读者要求直接讲解时，按本篇连贯推导讲清，不反复问已会先修。静态例、实验、练习必须使用本包同一输入和单位；实例价、合成价、模型价、规则时点不能混换。练习要给完整解析，不仅打分。仅当选读分支被采用时，将其optional reading转入当前必读。


Before substantive teaching, actually retrieve every required reading unit for the selected scope. Read its complete designated section, including necessary assumptions, tables and footnotes. A working URL or an editorial access date is not a runtime reading receipt. Record the actual version, location, scope and what it supports. If unavailable, use a previously verified equivalent source; if the required unit remains unavailable, identify that gap rather than teach it from memory. Start runtime_reading_log empty. Once reading is complete, use a substantive diagnostic or follow the reader's request for direct explanation. Advance one complete reasoning task at a time; skip mastered basics. Distinguish original facts, supplied teaching assumptions and inference.

## Required readings and runtime protocol
```json
{
  "export_mode": "public",
  "required_readings": [
    {
      "source_id": "MEFG-OIC-DELTA",
      "version": "Undated; retrieved 2026-09-21",
      "access": {
        "kind": "html_full_text",
        "uri": "https://www.optionseducation.org/advancedconcepts/delta",
        "verified_access_at": "2026-09-21"
      },
      "required_unit": {
        "locator": "完整概念正文",
        "scope": "完整指定单元、必要脚注与表图；不以搜索摘要代替",
        "purpose": "带单位的局部敏感度与适用条件"
      },
      "supports": "局部价格敏感度和对冲单位；概率近似不能升级成P下概率恒等。",
      "id": "M19-READ-01",
      "title": "Delta",
      "authors": [
        "Options Industry Council"
      ],
      "retrieved_at": "2026-09-21"
    },
    {
      "source_id": "MEFG-OIC-GAMMA",
      "version": "Undated; retrieved 2026-09-21",
      "access": {
        "kind": "html_full_text",
        "uri": "https://www.optionseducation.org/advancedconcepts/gamma",
        "verified_access_at": "2026-09-21"
      },
      "required_unit": {
        "locator": "完整概念正文",
        "scope": "完整指定单元、必要脚注与表图；不以搜索摘要代替",
        "purpose": "带单位的局部敏感度与适用条件"
      },
      "supports": "delta的局部变化；全组合或做市商净gamma须另有持仓资料。",
      "id": "M19-READ-02",
      "title": "Gamma",
      "authors": [
        "Options Industry Council"
      ],
      "retrieved_at": "2026-09-21"
    },
    {
      "source_id": "MEFG-OIC-VEGA",
      "version": "Undated; retrieved 2026-09-21",
      "access": {
        "kind": "html_full_text",
        "uri": "https://www.optionseducation.org/advancedconcepts/vega",
        "verified_access_at": "2026-09-21"
      },
      "required_unit": {
        "locator": "完整概念正文",
        "scope": "完整指定单元、必要脚注与表图；不以搜索摘要代替",
        "purpose": "带单位的局部敏感度与适用条件"
      },
      "supports": "波动率参数的偏导和每百分点单位；IV不是独立的P下预测。",
      "id": "M19-READ-03",
      "title": "Vega",
      "authors": [
        "Options Industry Council"
      ],
      "retrieved_at": "2026-09-21"
    },
    {
      "source_id": "MEFG-OIC-THETA",
      "version": "Undated; retrieved 2026-09-21",
      "access": {
        "kind": "html_full_text",
        "uri": "https://www.optionseducation.org/advancedconcepts/theta",
        "verified_access_at": "2026-09-21"
      },
      "required_unit": {
        "locator": "完整概念正文",
        "scope": "完整指定单元、必要脚注与表图；不以搜索摘要代替",
        "purpose": "带单位的局部敏感度与适用条件"
      },
      "supports": "固定其余变量的日历时间局部敏感度；非所有欧式期权必然价值递减。",
      "id": "M19-READ-04",
      "title": "Theta",
      "authors": [
        "Options Industry Council"
      ],
      "retrieved_at": "2026-09-21"
    },
    {
      "source_id": "PFH-MIT-BSM",
      "version": "Fall 2010",
      "access": {
        "kind": "pdf_full_text",
        "uri": "https://ocw.mit.edu/courses/15-450-analytics-of-finance-fall-2010/0d1260b891a96241316d883d4f5bfaec_MIT15_450F10_lec02.pdf",
        "verified_access_at": "2026-09-21"
      },
      "required_unit": {
        "locator": "slides16–21完整单元",
        "scope": "完整指定单元、必要脚注与表图；不以搜索摘要代替",
        "purpose": "BSM模型假设/公式，解析与差分校验"
      },
      "supports": "常参数、无股息模型条件下价格/偏导与Q；不宣称完整连续时间定理证明。",
      "id": "M19-READ-05",
      "title": "15.450: Stochastic Calculus and Option Pricing",
      "authors": [
        "Leonid Kogan",
        "MIT OpenCourseWare"
      ],
      "retrieved_at": "2026-09-21"
    }
  ],
  "optional_readings": [],
  "runtime_reading_log": [],
  "supplied_inputs": {
    "content_version": "2026-09-21-MEFG-draft-v1",
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      "schema": "markets-mefg-adopted-inputs-v1",
      "content_version": "2026-09-21-MEFG-draft-v1",
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      ],
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        "source_version": "2026-09-21-v1",
        "source_sha256": "8489fd3b74f469c3424d32a2b0738280e4e83709f081dfb24282d9afcfa8804b",
        "source_pointer": "two_state / three_state_incomplete / three_state_augmented_complete",
        "identity": "Exact received QT-F/M21 frozen contract; file preserved byte-for-byte; generated browser data is a derived copy",
        "physical_up_probability_variants": [
          0.2,
          0.6,
          0.8,
          0.9
        ],
        "period_unit": "one abstract period; R is gross growth, not annual net rate"
      },
      "odd_equal_wealth": {
        "identity": "OCC ODD June2024 printed p61 hypothetical; exact interest versus rounded official display distinguished",
        "initial_wealth_usd": 5000,
        "spot_usd": 50,
        "strike_usd": 50,
        "premium_per_share_usd": 5,
        "shares_per_contract": 100,
        "stock_position_shares": 100,
        "mixed_contracts": 1,
        "all_option_contracts": 10,
        "mixed_cash_usd": 4500,
        "simple_annual_cash_rate": 0.0325,
        "horizon_years": 0.5,
        "terminal_spots_usd": [
          62,
          58,
          54,
          50,
          46,
          42,
          38
        ],
        "cost_convention": "No fees, tax or stock dividends in base; terminal economic payoff is not a funding guarantee for physical exercise"
      },
      "cash_examples": {
        "identity": "Synthetic amounts under documented product rules; not historical quotes/series/accounts",
        "equity_call": {
          "multiplier": 100,
          "contracts": 1,
          "strike": 100,
          "purchase_premium": 4,
          "later_underlying_bid": 105,
          "later_option_bid": 6,
          "later_option_ask": 6.2,
          "exercise_gross_cash_assumption": 10000,
          "exercise_model": "sequential gross payment first; no assumed netting/credit; broker policy not inferred"
        },
        "spxw_call": {
          "multiplier_usd_per_point": 100,
          "strike_points": 5000,
          "purchase_premium_points": 50,
          "settlement_value_points": 5025,
          "shares_delivered": 0
        },
        "uncovered_equity_call_margin": {
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          "multiplier": 100,
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          "initial_option_premium": 4,
          "later_spot": 120,
          "later_option_mark": 17,
          "base_fraction": 0.2,
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          "other_positions_or_broker_addons": false,
          "default_external_cash_available": 2200,
          "model": "cash collateral; liability is mark not daily futures VM; no external deposits beyond the explicitly displayed steps"
        }
      },
      "early_exercise_counterexample": {
        "identity": "Separate teaching market, not EXP-STATE-01",
        "spot": 50,
        "strike": 100,
        "up_factor": 1.2,
        "down_factor": 0.9,
        "gross_cash_growth_per_period": 1.02,
        "periods": [
          1,
          2
        ],
        "dividend": 0,
        "time_unit": "one abstract period; not a year; American exercise at every displayed node"
      },
      "parity_quotes": {
        "identity": "Separate synthetic quote/funding scenario; no friction toggle on EXP-STATE-01",
        "strike": 105,
        "gross_cash_growth": 1.02,
        "stock": {
          "bid": 99.95,
          "ask": 100.05
        },
        "call": {
          "bid": 5.8,
          "ask": 6.2
        },
        "put": {
          "bid": 8.7,
          "ask": 9.1
        },
        "extra_fee_per_underlying_unit": 0,
        "cost_convention": "same borrowing/lending, zero dividend European same K/T; all legs synchronous and fully fillable only by explicit teaching assumption",
        "execution_assumptions": {
          "borrowing": true,
          "stock_short": true,
          "synchronous": true,
          "depth": true,
          "exercise_terms_match": true
        },
        "default_capital_available": 1
      },
      "surface": {
        "experiment_id": "EXP-MEFG-IV-01",
        "identity": "Entirely synthetic SPX-sized European call/put quotes; actual multiplier/tick only; no historical chain",
        "quote_date": null,
        "spot_index_points": 5000,
        "annual_continuous_rate": 0.04,
        "annual_continuous_dividend_yield": 0,
        "dividend_note": "zero is teaching assumption, not S&P500 dividend forecast",
        "day_count": "ACT/365 teaching whole-day expiries",
        "strikes_points": [
          4500,
          5000,
          5500
        ],
        "maturities": [
          {
            "days": 30,
            "sigma_by_strike": [
              0.28,
              0.24,
              0.22
            ]
          },
          {
            "days": 90,
            "sigma_by_strike": [
              0.27,
              0.235,
              0.22
            ]
          },
          {
            "days": 180,
            "sigma_by_strike": [
              0.25,
              0.23,
              0.22
            ]
          }
        ],
        "quote_half_width_points": 0.2,
        "contract_multiplier_usd_per_point": 100,
        "min_quote_tick_below3": 0.05,
        "min_quote_tick_at_or_above3": 0.1,
        "greek_example": {
          "strike": 5000,
          "days": 90,
          "sigma": 0.235,
          "spot_changes_points": [
            50,
            500
          ],
          "vol_changes_absolute": [
            0.01,
            0.1
          ]
        },
        "validation_scope": "displayed grid only; not a global no-arbitrage surface or observed chain"
      },
      "vix": {
        "official_sample": {
          "identity": "Methodology v6.0 Appendix3 explicitly hypothetical (2022-09-27 10:45:15 ET label is not observed VIX)",
          "minutes_near": 34484,
          "minutes_next": 44954,
          "target_minutes": 43200,
          "year_minutes": 525600,
          "near_variance": 0.019233906,
          "next_variance": 0.019423884,
          "displayed_T_near": 0.0656088,
          "displayed_T_next": 0.0855289,
          "displayed_vix": 13.93,
          "one_strike": {
            "strike": 1370,
            "delta_K": 5,
            "mid_quote": 0.2,
            "R_rounded": 0.000317,
            "T_rounded": 0.0656088,
            "displayed_contribution": 5.328e-07
          }
        },
        "two_term_teaching_variant": {
          "identity": "separate variance interpolation, not a VIX-strip reproduction",
          "days_near": 24,
          "days_next": 36,
          "target_days": 30,
          "near_vol": 0.2,
          "next_vol": 0.24
        }
      },
      "information_example": {
        "identity": "Synthetic contract volumes classified by initiating side; size-weighted KIT Eq(2), not unweighted transaction counts; not motives",
        "unit": "option contracts",
        "buyer_call_contracts": 30,
        "seller_call_contracts": 10,
        "buyer_put_contracts": 25,
        "seller_put_contracts": 35,
        "non_event_mean_TOI": 0.05,
        "baseline_window": "non-announcement days tau-40 through tau-10 per paper; 0.05 here a teaching value",
        "table_2_column_3": {
          "identity": "published regression coefficients with macro/non-macro separately standardized variables; not raw-return slopes/profits",
          "OI_coefficient": 0.0033,
          "OI_macro_interaction": 0.025,
          "column_1_OI_coefficient": 0.0078,
          "sample_observations": 51522
        }
      },
      "runtime_reading_log": []
    },
    "additional_files": [],
    "experiment_id": "EXP-MEFG-M19-GREEKS"
  },
  "entry_id": "zh-m19",
  "node_id": "M19",
  "content_version": "2026-09-21-MEFG-review-v3",
  "experiment_ids": [
    "EXP-MEFG-M19-GREEKS"
  ],
  "source_id_aliases": {
    "MEFG-ODD": "MA-OCC",
    "MEFG-OCC-EQUITY": "PFH-EQUITY",
    "MEFG-OCC-ETF": "PFH-ETF",
    "MEFG-OIC-T1": "PFH-T1",
    "MEFG-SPX": "MA-SPX",
    "MEFG-MIT-OPTIONS": "PFH-MIT-OPTIONS",
    "MEFG-MIT-KOGAN": "PFH-MIT-BSM",
    "MEFG-OIC-PARITY": "PFH-PARITY",
    "MEFG-OIC-EXERCISE": "PFH-EXERCISE",
    "MEFG-CHICAGOFED-2025": "PFH-CHIFED2025"
  },
  "source_paths": {
    "shared_inputs.json": "https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/inputs.json",
    "data/qt-f-shared-state-experiment.json": "https://ou-liu-red-sugar.github.io/notebook/labs/qt-f/data/qt-f-shared-state-experiment.json",
    "static/M19.html": "https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/static/M19.html"
  }
}
```

## Supplied entry
<a id="m19-variables"></a>
## 一、先问“对哪个变量求导”

上一篇用价格模型把报价变成IV。本篇暂时固定模型，问一个更局部的问题：如果一个输入稍微改变，当前价格大约怎样改变？Greeks就是把这个问题按不同变量拆开。它们不是关于下一步涨跌的独立预测，也不是在任何变动幅度下都精确的赔付规则。

令期权价格为 $V(S,\sigma,\tau,r,q_{\rm div})$，其中 $\tau$ 是剩余年数。固定其他变量，
$$
\Delta=\frac{\partial V}{\partial S},\qquad
\Gamma=\frac{\partial^2V}{\partial S^2},\qquad
\text{Vega}_{\rm abs}=\frac{\partial V}{\partial\sigma}.
$$
若用日历时间前进一日来定义theta，固定到期日时剩余年数减少 $1/365$，本篇的日theta是 $-\frac1{365}\frac{\partial V}{\partial\tau}$。有些资料按年、交易日或其他单位报告，数值不能不经换算就拼在一张表上。[^MEFG-OIC-DELTA][^MEFG-OIC-GAMMA][^MEFG-OIC-VEGA][^MEFG-OIC-THETA]

<a id="m19-default"></a>
## 二、固定同一张合成call，给每个数标单位

使用与价格一篇完全相同的合成切片：$S=K=5,000$，$\tau=90/365$，$r=4\%$，$q_{\rm div}=0$，$\sigma=23.5\%$，欧式call，乘数100美元／期权点。我们不是从某个真实期权链取得这些Greeks，而是从同一BSM函数计算。[^MEFG-MIT-KOGAN]

| 对象 | 默认值 | 单位及解释 |
|---|---:|---|
| 价格 | 256.855895 | 期权报价点 |
| delta | 0.556803 | 每变动1指数点，期权点数的局部变化 |
| gamma | 0.000676807 | 每变动1指数点，delta的局部变化 |
| vega | 9.804437 | 波动率提高**1个百分点**时，期权点数的局部变化 |
| theta | −1.556972 | 日历前进1日时，固定其余输入的局部变化 |
| 合约乘数 | 100 | 每期权报价点对应美元 |

一份合约的delta金额敏感度约为55.68美元／指数点；vega约为980.44美元／波动率百分点。将 $\sigma$ 从0.235变成0.245是提高1个百分点，而不是把 $\sigma$ 加1。若使用数学导数 $\partial V/\partial\sigma$，其数值应比每百分点vega大100倍。

SPX指数也不是可直接买入的“一股股票”。0.556803可以是模型对冲比率的起点，但实际用何种ETF、期货或组合实施，需要再做单位、基差和可成交性转换；这张表只给模型对指数水平的导数。[^MEFG-SPX]

<a id="m19-curvature"></a>
## 三、一次移动50点与500点，近似误差会发生什么

只改变 $S$ 时，泰勒展开给出
$$
\Delta V\approx\Delta\,\Delta S
+\frac12\Gamma(\Delta S)^2.
$$
保留第一项是delta近似，加入第二项是delta加gamma近似。这里的 $\Delta,\Gamma$ 都在**起点**计算，不是在看到终点以后重新选择。

| 标的变动 | delta一阶变化 | delta＋gamma二阶变化 | 完整BSM重算变化 |
|---:|---:|---:|---:|
| ＋50指数点 | 27.840133 | 28.686142 | 28.679412 |
| ＋500指数点 | 278.401326 | 363.002261 | 353.164687 |

对50点变动，一阶少算约0.839279点；二阶误差仅约0.006730点。对500点变动，二阶仍然比一阶更近，却高出约9.837574点。现金误差还要乘100。**加入gamma不是给近似加一个“精确保证”，而是多保留一阶曲率信息。**

曲率为正也可以从图上读出来：call价格随 $S$ 上升时斜率逐渐变大，起点切线会低于完整凸曲线。但移动大时，gamma自身也变；沿全区间使用起点gamma，仍是近似。OIC的局部解释和MIT的价格模型在这里各承担一层：一个教你导数意义，一个提供可重新计算的函数。[^MEFG-OIC-GAMMA][^MEFG-MIT-KOGAN]

<a id="m19-vol-time"></a>
## 四、波动率和时间的单位同样会放大错误

把 $S$ 固定，改 $\sigma$。本例的每百分点vega给出的比较为：

| 波动率变化 | vega局部预测 | 完整重算 |
|---:|---:|---:|
| 23.5% → 24.5% | ＋9.804437点 | ＋9.805146点 |
| 23.5% → 33.5% | ＋98.044371点 | ＋98.067826点 |

这一次大幅变化下误差仍小，是本切片的具体结果，不是vega在所有行权价、期限上都线性的证据。换到临近到期或远离平值的合约，敏感度形状会不同。

日theta为−1.556972，意思是保持现价、模型波动率、利率和股息输入不变，日历时间前进一日的局部效应。真实市场到明天会同时改变许多输入，所以不能把theta直接当作明天必然少掉的价格。欧式put还可能因收取 $K$ 的时点接近而出现正的日历时间效应；上一篇的深度价内反例正说明“持有期权每天必亏时间价值”不是无条件定理。[^MEFG-OIC-THETA]

若同时改变 $S,\sigma$ 和日历时间，可以先加起点delta、gamma、vega、theta项作局部估算，但跨变量项以及各导数的变化并不会消失。本实验同时展示完整重算，避免把这类估算结果误当成真实账户路径。

<a id="m19-probability"></a>
## 五、delta不是“上涨概率”

在本无股息BSM call中，delta等于 $N(d_1)$；同模型定价概率下的到期价内概率为 $N(d_2)$。本例两者分别为
$$
N(d_1)=0.556803,\qquad N(d_2)=0.510441.
$$
即使在这个非常规则的模型里，它们已经不同；更不能把任意产品的delta直接解释成现实概率 $P$ 下的胜率。[^MEFG-MIT-KOGAN]

把一项价格导数叫成概率，常常是因为0到1之间的数看起来很像概率。但是它们的定义不同：delta问“当前价格对输入怎样变”，价内概率问“在某个概率模型下哪些终值状态发生”；还要再区分定价权重 $Q$ 和现实／研究概率 $P$。后面复制一篇会从交易资产价格解释这种权重区别。

<div data-experiment-slot="EXP-MEFG-M19-GREEKS"></div>

实验第一视角画完整价格曲线、起点切线和起点二阶曲线；第二视角比较两种近似相对于完整重算的误差。默认可直接选50点和500点，或者改波动率百分点、时间天数。切到美元显示时只做100倍单位换算，不改变模型。

<a id="m19-exercises"></a>
## 六、把“近似”写进答案

**题一。** 一份本例call，指数上升50点，delta近似的美元变化是多少？二阶与完整重算分别是多少？

**解析。** 期权点变化依次为27.840133、28.686142和28.679412，乘100得到约2,784.01、2,868.61和2,867.94美元。不要再乘一次5,000，也不要把delta当作要买入0.556803股“指数股票”的实盘指令。

**题二。** 某人把每百分点vega 9.804437乘以0.01，计算波动率从23.5%变24.5%的变化。错在哪里？

**解析。** 9.804437本来已经是每一个百分点的报价量，应乘1。若要乘0.01，应使用按一整个绝对 $\sigma$ 单位报告的导数980.443707。两种单位正确换算后结果相同。

**题三。** 本例500点移动中二阶近似高于完整重算，是否否定gamma为正？

**解析。** 没有。gamma为正是价格函数在起点的曲率信息；大区间移动时曲率本身改变，还存在更高阶项。二阶多项式不是整条价格函数。

**题四。** delta为0.556803，能否宣称“我有55.68%的真实概率盈利”？

**解析。** 不能。首先delta是导数，本例连 $Q$ 下的价内概率都只有0.510441；其次价内不等于覆盖权利金后盈利；最后 $Q$ 不等于现实 $P$。这三个区别要依次保留。

[^MEFG-OIC-DELTA]: Options Industry Council，*Delta*，Undated; retrieved 2026-09-21。[原文](https://www.optionseducation.org/advancedconcepts/delta)。本篇定位：Full main concept body。

[^MEFG-OIC-GAMMA]: Options Industry Council，*Gamma*，Undated; retrieved 2026-09-21。[原文](https://www.optionseducation.org/advancedconcepts/gamma)。本篇定位：Full main concept body。

[^MEFG-OIC-VEGA]: Options Industry Council，*Vega*，Undated; retrieved 2026-09-21。[原文](https://www.optionseducation.org/advancedconcepts/vega)。本篇定位：Full main concept body。

[^MEFG-OIC-THETA]: Options Industry Council，*Theta*，Undated; retrieved 2026-09-21。[原文](https://www.optionseducation.org/advancedconcepts/theta)。本篇定位：Full main concept body。

[^MEFG-MIT-KOGAN]: Leonid Kogan, MIT OpenCourseWare，*15.450: Stochastic Calculus and Option Pricing*，Fall 2010。[原文](https://ocw.mit.edu/courses/15-450-analytics-of-finance-fall-2010/0d1260b891a96241316d883d4f5bfaec_MIT15_450F10_lec02.pdf)。本篇定位：Slides 16–21: BSM market, replication/PDE/formula；Slides 52–58 and 60: Q pricing and European application。

[^MEFG-SPX]: Cboe Global Markets，*S&P 500 Index Options (SPX) Fact Sheet*，©2026; WF-451400-KC; no precise issue date shown。[原文](https://cdn.cboe.com/resources/spx/spx-fact-sheet.pdf)。本篇定位：Full physical pp1–2; p2 specifications and relevant footnotes。

<script src="/notebook/labs/m-efg/reader-adapter.js" defer></script>


## Additional teaching material
### 本篇默认结果与静态等价

<div class="table-wrap"><table><thead><tr><th>初始敏感度</th><th>数值</th><th>单位</th></tr></thead><tbody><tr><td>delta</td><td>0.556802653</td><td>点/标的点</td></tr><tr><td>gamma</td><td>0.000676807476</td><td>delta/标的点</td></tr><tr><td>vega</td><td>9.804437069</td><td>点/1波动率百分点</td></tr><tr><td>theta</td><td>-1.556972481</td><td>点/日</td></tr><tr><td>N(d2)</td><td>0.510441217</td><td>Q模型概率，不是P</td></tr></tbody></table></div><div class="table-wrap"><table><thead><tr><th>S变化</th><th>一阶</th><th>加spot二阶</th><th>全模型</th></tr></thead><tbody><tr><td>50</td><td>27.840133</td><td>28.686142</td><td>28.679412</td></tr><tr><td>500</td><td>278.401326</td><td>363.002261</td><td>353.164687</td></tr></tbody></table></div><p>每合约点数乘100美元。以上只改S，其余不变；同时改波动率与时间时，一阶加vega/theta，未计全部交叉二阶项。</p>

完整冻结输入：https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/inputs.json。来源内的包路径按 source_paths 取得。

## Experiment inputs and static equivalents
```json
[
  {
    "id": "EXP-MEFG-M19-GREEKS",
    "title": "局部近似与完整重新定价",
    "anchor": "m19-probability",
    "description": "小变动和大变动各算一次；点数、美元和波动率百分点分别显示。",
    "data_identity": "同一90天、K=5,000、σ=23.5%的合成切片；不是实时Greeks。",
    "shared_dataset_ids": [
      "EXP-MEFG-IV-01"
    ],
    "inputs": {
      "canonical_common": "shared_inputs.json",
      "state_contract": null,
      "controls": [
        {
          "name": "ds",
          "label": "标的变化（指数点）",
          "type": "number",
          "default": 50,
          "domain_or_choices": {
            "min": -4000,
            "max": 5000,
            "step": 50
          }
        },
        {
          "name": "dvPpt",
          "label": "波动率变化（百分点）",
          "type": "number",
          "default": 0,
          "domain_or_choices": {
            "min": -20,
            "max": 100,
            "step": 1
          }
        },
        {
          "name": "elapsedDays",
          "label": "经过的日历天数",
          "type": "number",
          "default": 0,
          "domain_or_choices": {
            "min": 0,
            "max": 89,
            "step": 1
          }
        },
        {
          "name": "unit",
          "label": "结果单位",
          "type": "select",
          "default": "points",
          "domain_or_choices": [
            [
              "points",
              "期权报价点"
            ],
            [
              "usd",
              "每合约美元（×100）"
            ]
          ]
        }
      ]
    },
    "algorithm": "Compute analytic delta,gamma,vega_per_ppt=vega*.01,theta_per_day=theta_year/365 at shared base. Linear ΔC=delta*ΔS+vega_ppt*Δsigma_ppt+theta_day*elapsed; partial second-order adds .5*gamma*ΔS². Exact BSM at new S,sigma,T; errors report approximate-exact; dollar scale=100.",
    "outputs": {
      "default": {
        "base": {
          "price": 256.85589455779245,
          "delta": 0.5568026529513653,
          "gamma": 0.0006768074761722486,
          "vegaPerPpt": 9.804437069207575,
          "thetaPerDay": -1.556972481378402,
          "qITM": 0.5104412165596846,
          "d1": 0.14286766759947472,
          "d2": 0.026175237306540852
        },
        "ds": 50,
        "dvPpt": 0,
        "elapsedDays": 0,
        "linear": 27.840132647568268,
        "quadratic": 28.68614199278358,
        "exact": 28.67941201992653,
        "errorLinear": -0.8392793723582628,
        "errorQuadratic": 0.006729972857048239,
        "exactCash": 2867.941201992653,
        "multiplier": 100,
        "limitation": "delta/gamma curvature only in S; cross/time/vol second derivatives omitted"
      },
      "static_equivalent": "https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/static/M19.html",
      "unit_note": "同一90天、K=5,000、σ=23.5%的合成切片；不是实时Greeks。"
    },
    "boundaries": [
      "Telapsed<90且新S和sigma为正",
      "vega单位百分点、theta日、multiplier100",
      "只加入spot二阶，交叉和高阶未覆盖",
      "N(d2)≠P概率，delta≠N(d2)"
    ],
    "views": {
      "first": "数值/单位/现金表",
      "second": "定价、现金、状态或事件图；见同一实验实现"
    },
    "implementation": {
      "html": "/notebook/labs/m-efg/interactions.html?experiment=EXP-MEFG-M19-GREEKS",
      "engine": "/notebook/labs/m-efg/engine.js",
      "static_available_without_js": true
    },
    "source_id_aliases": {
      "MEFG-ODD": "MA-OCC",
      "MEFG-OCC-EQUITY": "PFH-EQUITY",
      "MEFG-OCC-ETF": "PFH-ETF",
      "MEFG-OIC-T1": "PFH-T1",
      "MEFG-SPX": "MA-SPX",
      "MEFG-MIT-OPTIONS": "PFH-MIT-OPTIONS",
      "MEFG-MIT-KOGAN": "PFH-MIT-BSM",
      "MEFG-OIC-PARITY": "PFH-PARITY",
      "MEFG-OIC-EXERCISE": "PFH-EXERCISE",
      "MEFG-CHICAGOFED-2025": "PFH-CHIFED2025"
    },
    "input_uri": "https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/inputs.json",
    "static_equivalent": "https://ou-liu-red-sugar.github.io/notebook/labs/m-efg/static/M19.html"
  }
]
```

## Sources
- [SPX Options Fact Sheet](https://cdn.cboe.com/resources/spx/spx-fact-sheet.pdf): 现金结算、欧式行权、100美元乘数及SPX/SPXW结算差别；不采用营销/税务部分。

SPXW欧式、PM、每点100美元、现金于到期后营业日交付；传统SPX AM/SOQ与SPXW分开。无实际报价。

M-E/F/G 本批采用：SPX/SPXW欧式现金、100美元乘数、最小报价增量及AM/PM结算差别；并非某条历史上市期权链。
- [Delta](https://www.optionseducation.org/advancedconcepts/delta): 局部价格敏感度和对冲单位；概率近似不能升级成P下概率恒等。
- [Gamma](https://www.optionseducation.org/advancedconcepts/gamma): delta的局部变化；全组合或做市商净gamma须另有持仓资料。
- [Theta](https://www.optionseducation.org/advancedconcepts/theta): 固定其余变量的日历时间局部敏感度；非所有欧式期权必然价值递减。
- [Vega](https://www.optionseducation.org/advancedconcepts/vega): 波动率参数的偏导和每百分点单位；IV不是独立的P下预测。
- [15.450 Stochastic Calculus and Option Pricing](https://ocw.mit.edu/courses/15-450-analytics-of-finance-fall-2010/0d1260b891a96241316d883d4f5bfaec_MIT15_450F10_lec02.pdf): 无分红、常利率/常波动率模型、复制、PDE与BSM公式；本例采用r=0，非一般American模型或实际概率。

M-E/F/G 本批采用：常参数、无股息模型条件下价格/偏导与Q；本批数值只采用q=0版本，不把非零股息扩展归给该读取单元；不宣称完整连续时间定理证明。

## Content relations
```json
[
  {
    "from": "zh-m19",
    "relation": "part_of",
    "to": "markets-derivatives",
    "reason": "主要 topic 归属"
  },
  {
    "from": "zh-m19",
    "relation": "requires",
    "to": "zh-m18",
    "reason": "仅需要这项先备能力，不由推荐次序自动生成",
    "required_competence": "能说明模型输入、IV及价格函数"
  },
  {
    "from": "m19-variables",
    "relation": "supported_by",
    "to": "MEFG-OIC-DELTA",
    "reason": "局部价格敏感度和对冲单位；概率近似不能升级成P下概率恒等。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-variables"
  },
  {
    "from": "m19-variables",
    "relation": "supported_by",
    "to": "MEFG-OIC-GAMMA",
    "reason": "delta的局部变化；全组合或做市商净gamma须另有持仓资料。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-variables"
  },
  {
    "from": "m19-variables",
    "relation": "supported_by",
    "to": "MEFG-OIC-VEGA",
    "reason": "波动率参数的偏导和每百分点单位；IV不是独立的P下预测。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-variables"
  },
  {
    "from": "m19-variables",
    "relation": "supported_by",
    "to": "MEFG-OIC-THETA",
    "reason": "固定其余变量的日历时间局部敏感度；非所有欧式期权必然价值递减。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-variables"
  },
  {
    "from": "m19-default",
    "relation": "supported_by",
    "to": "PFH-MIT-BSM",
    "reason": "常参数、无股息模型条件下价格/偏导与Q；不宣称完整连续时间定理证明。",
    "locator": "Slides 16–21: BSM market, replication/PDE/formula；Slides 52–58 and 60: Q pricing and European application",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-default"
  },
  {
    "from": "m19-default",
    "relation": "supported_by",
    "to": "MA-SPX",
    "reason": "SPX/SPXW欧式现金、100美元乘数、最小报价增量及AM/PM结算差别；并非某条历史上市期权链。",
    "locator": "Full physical pp1–2; p2 specifications and relevant footnotes",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-default"
  },
  {
    "from": "m19-curvature",
    "relation": "supported_by",
    "to": "MEFG-OIC-GAMMA",
    "reason": "delta的局部变化；全组合或做市商净gamma须另有持仓资料。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-curvature"
  },
  {
    "from": "m19-curvature",
    "relation": "supported_by",
    "to": "PFH-MIT-BSM",
    "reason": "常参数、无股息模型条件下价格/偏导与Q；不宣称完整连续时间定理证明。",
    "locator": "Slides 16–21: BSM market, replication/PDE/formula；Slides 52–58 and 60: Q pricing and European application",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-curvature"
  },
  {
    "from": "m19-vol-time",
    "relation": "supported_by",
    "to": "MEFG-OIC-THETA",
    "reason": "固定其余变量的日历时间局部敏感度；非所有欧式期权必然价值递减。",
    "locator": "Full main concept body",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-vol-time"
  },
  {
    "from": "m19-probability",
    "relation": "supported_by",
    "to": "PFH-MIT-BSM",
    "reason": "常参数、无股息模型条件下价格/偏导与Q；不宣称完整连续时间定理证明。",
    "locator": "Slides 16–21: BSM market, replication/PDE/formula；Slides 52–58 and 60: Q pricing and European application",
    "scope": "本段具名采用内容；教学生成数字仍按自身身份",
    "at_section": "m19-probability"
  },
  {
    "from": "m19-probability",
    "relation": "illustrated_by",
    "to": "EXP-MEFG-M19-GREEKS",
    "reason": "小变动和大变动各算一次；点数、美元和波动率百分点分别显示。",
    "at_section": "m19-probability"
  }
]
```

## Related entries
