Why Deep In-the-Money Option Expiry May Not Create a Trading Edge
Summary
The document considers whether the ratio of deep in-the-money call and put open interest or volume could predict buying or selling in the underlying after expiration. The response explains the idea through delta hedging: an option dealer or counterparty commonly adjusts an offsetting share position as the option’s delta changes. A deep in-the-money call has a delta near one, so the hedge can approach the number of shares delivered on exercise.
Because the hedge is adjusted during the option’s life, the share exposure associated with exercise is generally offset by positions already accumulated. On this reasoning, expiration does not necessarily create a fresh directional flow that can be inferred from the call-to-put ratio; any adjustment may have occurred earlier. The answer offers a simplified single-option illustration, not an empirical test of open-interest signals. It does not quantify the effect across market participants, discuss imperfect hedging or settlement details, or provide a paper review, so the conclusion should be treated as a conceptual explanation rather than a demonstrated universal result.
Key ideas
- Deep in-the-money options approach a delta of one as expiration nears.
- Delta hedgers adjust their underlying positions over the life of an option.
- Those accumulated hedge positions can offset the shares delivered or received at exercise.
- An expiration-day signal based only on deep in-the-money call and put ratios may therefore miss when hedging flows occurred.
- The explanation is conceptual and does not empirically test the proposed ratio as a trading signal.
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Full text
# Is there an advantage trading options based on deep in the money Open Interest Volume ratio # Is there an advantage trading options based on deep in the money Open Interest Volume ratio #### Problem: - Deep in the money options contracts will be assigned at expiration date. - Higher Volume ratio of deep in the money contracts at expiration calls or puts leads to day after expiration date we have more traders holding the underlying asset or disposing based on calls to put ratio below or above 1. #### Question: Does this make any sense? Is there any paper research on this topic? ## Answer by MonteCarloSims (score 4) https://quant.stackexchange.com/a/44368 I don't mean to suggest such a large topic, but it would certainly be worth reading about delta-hedging with regards to your question. Since such a large percentage of options are delta-hedged, the net price change of shares in the underlying due to exercise on expiration would be ~0. As @Emma mentioned, deep in the money options have a high delta. This leads to a large ratio of an opposite & offsetting position in shares being put on immediately. > Example: Buy to open one SPY 100 Call, Delta ~0.98 Counterparty sells to open the option and immediately buys 98 SPY shares. As expiration approaches, delta will approach 1. As it hits 0.99, an additional share will be bought. As it hits 1 (near expiration), only a single additional share will be bought. The delta-hedging counterparty will then own 100 shares as the call is exercised and the 100 shares are assigned to the option buyer. In answer to your question, essentially any benefit that might have been gained at expiration has been distributed throughout the life of the option contract. The changes in these offsetting positions are more pronounced at lower deltas, but in-the-money options will always end in a delta of 1. They will have been continuously adjusted and will therefore have a fully offset position by their expiration date.
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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.