CONTENTS

Exercise: Extracting implied forward from market quotes

For the 1-year options on SPY, you observe the following market mid-quotes:

Strike KKCall CCPut PP
40059.8013.40
42047.2020.60
44036.1529.35
46026.7039.70

Assume r=5%r = 5\%, no short-sale constraints.

Tasks

  1. For each strike, compute CPC - P, then extract the "implied forward price" FK=K+erT(CP)F_K = K + e^{rT}(C - P).

  2. If the market is arbitrage-free, FKF_K should be the same across all strikes. Do the four values agree?

  3. If you observed FKF_K with noticeable variation, what would it tell you about the market?

  4. The SPY spot price is S0=440S_0 = 440. The "implied dividend yield" satisfies F=S0e(rq)TF = S_0 e^{(r - q)T}. Extract qq.

Hint

erT=e0.051.05127e^{rT} = e^{0.05} \approx 1.05127.