The market is seeing increased selling pressure so far this morning. I don't think it is due to anything more than pre-Fed jitters.
The ARMS index is above average at 1.50. The CBOE put/call ratio is also slightly elevated at 0.93. The ISEE is also showing slightly elevated levels of bearishness at 138.
I am staying a bit cautious here, as anything can happen on Fed days. But I will look to add to my long exposure if weakness lasts a couple of days.