Reading the HSI Options Strike Wall · 解讀恒指期權行使價牆

Research Note · 研究筆記

On the hkstock.observer dashboard, the Options Strike Wall visualizes the largest Put and Call open interest (OI) for the next three HSI options expiry months. This is not just a chart — it is a map of where the largest institutional option writers have concentrated their risk, and where the index is statistically most likely to pin or reverse.

在 hkstock.observer 儀表板上，期權行使價牆視覺化了未來三個恒指期權到期月中，最大的 Put 與 Call 未平倉合約（OI）。這不僅僅是圖表，而是大型機構期權賣方集中風險之處，亦即指數最可能釘住或反轉之處。

Why Open Interest Matters · 為什麼未平倉合約重要

Open interest represents the total number of outstanding option contracts. When OI is heavily concentrated at a specific strike price (e.g., 20,000 for Puts or 22,000 for Calls), it means market makers who sold those options must hedge their exposure by buying or selling the underlying HSI futures. This hedging activity creates a "magnet" or "wall" effect.

未平倉合約代表未結清的期權合約總數。當 OI 高度集中於某一行使價（例如 Put 20,000 或 Call 22,000），賣出這些期權的莊家必須買賣恒指期貨來對沖風險。這種對沖活動產生了「磁石」或「牆」效應。

How to Trade the Walls · 如何利用行使價牆交易

• The Call Wall (Resistance): The strike with the largest Call OI acts as near-term resistance. As the index approaches this level, market makers may sell futures to remain delta-neutral, capping the upside.
  Call 牆（阻力）：最大 Call OI 的行駛價充當短線阻力。當指數接近此水平，莊家可能賣出期貨以保持 Delta 中性，從而限制升幅。
• The Put Wall (Support): The strike with the largest Put OI acts as near-term support. If the index drops to this level, market makers may buy futures to hedge, creating a floor.
  Put 牆（支撐）：最大 Put OI 的行駛價充當短線支撐。若指數跌至該水平，莊家可能買入期貨對沖，形成底部。
• OI Change Arrows: The daily change arrows (↑/↓) show where new money is flowing. A rapidly building Call wall suggests institutional players are betting on (or hedging against) an upside breakout.
  OI 變動箭頭：每日變動箭頭顯示新資金流向。快速堆積的 Call 牆暗示機構正押注（或對沖）向上突破。