Abstract
Documenting spread and combination trading in a major options market for the first time, we find that spreads and combinations collectively account for over 55% of large trades (trades of 100 contracts or more) in the Eurodollar options market and almost 75% of the trading volume due to large trades. In terms of total volume, the four most heavily traded combinations are (in order): straddles, ratio spreads, vertical spreads, and strangles. These four represent about two thirds of all combination trades. On the other hand, condors, horizontal spreads, guts, iron flys , box spreads, guts, covered calls or puts, and synthetics are very rarely traded while trading is light in collars, diagonal spreads, butterflies, straddle spreads, seagulls, doubles, and delta-neutral combinations. Significant differences in size, cost, and time-to-expirations are found among the various combination types.
Our results confirm that traders use spreads and combinations to construct portfolios which are highly sensitive to some risk factors and much less sensitive to other risk factors. The most popular combination designs are those yielding portfolios which are quite sensitive to volatility and less sensitive to directional changes in the underlying asset value – though they are often not completely delta neutral. Among these, combinations which are short volatility significantly out-number those which were long. Among the minority of combinations which are highly sensitive to the underlying asset price, those with positive deltas significantly outnumber those with negative deltas indicating that traders are using this market to bet on or hedge against an increase in the LIBOR rate.
We find evidence that effective bid/ask spreads are larger on orders exceeding 500 contracts or more than on orders of between 100 and 500 contracts and evidence that effective bid/ask spreads are larger on combinations which short volatility.