On Yahoo (http://finance.yahoo.com/q/op?s=AMZN&m=2014-01) , there are two PUT options for AMZN with strike price 225 expiring on Jan 17 2014: AMZN140118P00225000 and AMZN7140118P00225000. I guess I have two questions:
1. shouldn't there be only one PUT option with that underlying / strike / expiryt date?
2. what is the difference between these two PUT options?