A decisive u-turn off yearly lows qualifies as a key reversal day for the major indexes.

New lows beneath key support lines usually triggers heavy selling, often draining the market of that supply, which opens the door for Bulls to come in and move the ball higher.

Think of this as a the Bear’s train running out of steam, or better yet, the herd getting slaughtered, which is pretty much the norm in market action.

But how long today’s late-day rally can last is to be determined.

Should we rally from here, we’ll want to see heavy buy volume come in as a show of confidence from institutions for higher prices.