Quote from yip1997:
MTE,
Thanks a lot. I have a risk profile modeled by TOS. The price difference was 2.3 this morning.
Does it mean there was an arb profit of 0.15? How come the risk profile (long put calendar and short call calendar) is not flat at Feb expiration.
I don't think it was an arb, just a bid ask spread.
There was a good chat session on calendar spreads some time ago at TOS, look it up in chat transcripts.