There has been a lot of talk lately on the twitter stream about the market rallying into options expiration and then giving up all the gains. There is some truth to that, and the fact that we are at or near resistance levels (read) one should be aware of what has happened after options expiration.
Underneath what you are looking at is the SPY starting the Monday after options expiration through the next ten days. Every month has shown some weakness after expiration and the context of every month has been the same, a rally up to expiration. August was the only month that we did not see a rally leading up to options expiration.