波動率偏斜是什麼?微笑曲線實測
波動率偏斜讓下行賣權比上行買權貴。我們逐個履約價測量SPY,再掃描全市場選擇權鏈,量化崩盤保險的溢價與少數反轉案例。
波動率偏斜是指同一檔股票、相同到期日的不同履約價,在選擇權鏈上以不同的隱含波動率交易。教科書裡,每個履約價只會對應一個波動率。但在真實報價中,下行履約價幾乎總是更貴——這是市場自1987年崩盤以來一直存在的傾斜,而且可以直接量化。
SPY 的偏斜,逐個履約價檢視
以下是實際曲線:SPY 的價外選擇權,單一到期區間,依履約價水準排列的隱含波動率,取自真實收盤價:
每個數據背後的精確 SQL 語法
SELECT concat(toString(round(100 * b)), '% of spot') AS strike_vs_spot,
round(100 * median(implied_volatility), 1) AS otm_iv_pct
FROM (
SELECT implied_volatility, round(strike_price / underlying_close / 0.05) * 0.05 AS b, option_type
FROM global_markets.options_greeks
WHERE underlying_symbol = 'SPY' AND date = toDate('2026-07-15')
AND iv_converged AND implied_volatility BETWEEN 0.02 AND 5
AND strike_price / underlying_close BETWEEN 0.83 AND 1.12
AND expiration_date BETWEEN date + 20 AND date + 45
)
WHERE (b < 1 AND option_type = 'P') OR (b > 1 AND option_type = 'C') OR b = 1
GROUP BY b
HAVING count() >= 10
ORDER BY b從左到右解讀:履約價低於市價15%的賣權,隱含波動率為 27.5%;價平水準為 13.4%;履約價高於市價5%的買權最便宜,為 10.5%。相同標的,相同到期日——唯一改變的是履約價,而市場對深度下行收取超過兩倍的波動率。崩盤保險比樂透彩券更貴;這張圖就是那句話的圖像化。
這種偏斜是否普遍?全市場的衡量
每個數據背後的精確 SQL 語法
SELECT count() AS underlyings,
countIf(put_iv > call_iv) AS puts_richer,
round(100.0 * countIf(put_iv > call_iv) / count(), 1) AS pct_puts_richer,
round(100 * quantileExact(0.5)(put_iv - call_iv), 1) AS median_skew_points
FROM (
SELECT underlying_symbol,
medianIf(implied_volatility, option_type = 'P' AND strike_price / underlying_close BETWEEN 0.85 AND 0.95) AS put_iv,
medianIf(implied_volatility, option_type = 'C' AND strike_price / underlying_close BETWEEN 1.05 AND 1.15) AS call_iv
FROM global_markets.options_greeks
WHERE date = toDate('2026-07-15') AND iv_converged AND implied_volatility BETWEEN 0.02 AND 5
AND expiration_date BETWEEN date + 20 AND date + 60
GROUP BY underlying_symbol
HAVING countIf(option_type = 'P' AND strike_price / underlying_close BETWEEN 0.85 AND 0.95) >= 5
AND countIf(option_type = 'C' AND strike_price / underlying_close BETWEEN 1.05 AND 1.15) >= 5
AND sum(volume) >= 500
)
WHERE put_iv > 0 AND call_iv > 0在 348 檔兩側都有活躍選擇權鏈的標的中,70.4% 將其下行賣權定價高於上行買權,波動率點數的中位數差距為 2.2。賣權偏斜是市場的預設姿態——而例外之處,正是資訊所在。
反轉的尾部:上行成本更高的標的
每個數據背後的精確 SQL 語法
SELECT underlying_symbol AS ticker,
round(100 * call_iv, 1) AS otm_call_iv_pct,
round(100 * put_iv, 1) AS otm_put_iv_pct,
round(100 * (call_iv - put_iv), 1) AS call_over_put_points
FROM (
SELECT underlying_symbol,
medianIf(implied_volatility, option_type = 'P' AND strike_price / underlying_close BETWEEN 0.85 AND 0.95) AS put_iv,
medianIf(implied_volatility, option_type = 'C' AND strike_price / underlying_close BETWEEN 1.05 AND 1.15) AS call_iv
FROM global_markets.options_greeks
WHERE date = toDate('2026-07-15') AND iv_converged AND implied_volatility BETWEEN 0.02 AND 5
AND expiration_date BETWEEN date + 20 AND date + 60
AND underlying_symbol NOT IN ('KORU','SOXL','SOXS','TQQQ','SQQQ','NVDL','NVDS','NVD','TSLL','TSLQ','TSLZ','SPXL','SPXS','UPRO','SPXU','LABU','LABD','FAS','FAZ','TNA','TZA','YINN','YANG','UDOW','SDOW','BOIL','KOLD','UCO','SCO','USD','SSO','SDS','QLD','QID','ERX','ERY','DRN','DRV','CURE','SOXY','MUU','SNXX','UVXY','SVXY','UVIX','SVIX','BULZ','WEBL','WEBS','DPST','DRIP','GUSH','AGQ','ZSL','BITX','ETHU','MSTX','MSTU','CONL','DUST','JNUG','JDST','NUGT','AMDL','NUAI','VXX','VIXY')
GROUP BY underlying_symbol
HAVING countIf(option_type = 'P' AND strike_price / underlying_close BETWEEN 0.85 AND 0.95) >= 5
AND countIf(option_type = 'C' AND strike_price / underlying_close BETWEEN 1.05 AND 1.15) >= 5
AND sum(volume) >= 2000
)
WHERE put_iv > 0 AND call_iv > 0 AND call_iv > put_iv
ORDER BY call_over_put_points DESC
LIMIT 8大約每十檔中有三檔走相反方向,而最極端的案例相當戲劇化:ASTS 將其價外買權定價在 169.2%,相對於其賣權的 69.9%——上行額外多出 99.3 個波動率點數。反轉偏斜意味著選擇權市場將大幅上漲定價為尾部風險:潛在的軋空候選股、具有二元催化劑的標的,以及市場擔憂的情境是錯失漲勢而非崩盤的股票。槓桿型基金和波動率 ETP 已從此版面排除——它們的偏斜是結構性的,而非資訊性的。
偏斜對交易的意義
偏斜是一種相對價格,它會影響每一個多腿結構的經濟效益。保護性賣權的買方直接支付了這個偏斜——下行履約價是昂貴的一端。 collar 策略則收割了它:你買入的賣權很貴,但你賣出用以抵銷的買權也是根據同一條曲線定價,而在反轉偏斜的標的上,賣出買權能為避險提供更多資金。一檔股票所報價的隱含波動率數字,實際上是一整條曲線的數字,而你的履約價落在曲線上的哪個位置,就是你支付價格的一部分。
常見問題
什麼是波動率偏斜,用簡單的話來說?
同一檔股票、相同到期日的不同履約價,以不同的隱含波動率交易。在大多數標的中,低於市價的履約價,其隱含波動率高於高於市價的履約價——每單位波動率的下行保護成本,高於上行曝險成本。
為什麼賣權的隱含波動率通常高於買權?
需求與歷史因素:投資組合避險者持續買入下行賣權,賣方要求對崩盤風險進行補償,且市場下跌速度比上漲快。自1987年10月市場重新定價單日崩盤可能的面貌以來,此模式一直存在。
反轉偏斜意味著什麼?
買權定價高於賣權——市場將大幅上漲視為尾部情境。在本頁面的衡量日期,大約每十檔活躍標的中就有三檔呈現反轉,集中在潛在軋空股和具有二元催化劑的標的。
波動率偏斜與波動率微笑相同嗎?
屬於同一概念家族。「微笑」描述兩翼都高於價平水準的狀態;「偏斜」或「 smirk 」則描述不對稱的版本,其中一翼——幾乎總是賣權側——更高。股票指數通常呈現 smirk,正如上方 SPY 的曲線所示。
以上每個數字都是對全市場選擇權報價進行的、已儲存且具版本控制的查詢結果——展開任何面板即可審計,或從 Strasmore 終端衡量任何標的的偏斜。欲了解目前波動率本身最高的位置,請參見高 IV 版面;欲了解事件發生後這些價格的變化,請參見 IV crush。