It certainly looked like a breakout, at least for today, but it would have been more convincing if the volumes had not remained thin. As such it looked like a short squeeze engineered by the wiseguys ahead of the FOMC meeting.
SP 500
NDX
Saint Michael the Archangel, defend us in battle; be our protection against the wickedness and snares of the devil. May God rebuke him, we humbly pray: and you, Prince of the heavenly host, by the power of God, thrust into Hell Satan and all of the other evil spirits who prowl about the world seeking the ruin of souls.