I'm always wary of month-end signals because it usually represents forced flows and rebalancing rather than a fundamental view on the market or economy.

In any case, the S&P 500 has erased a more-than 40 point decline and is now trading higher on the day. With the rebound, it's also now higher on the month.

That's shaping up to carve out a big doji star on the chart. You have to go back a long way -- to Feb 2016 -- to find something similar and that was followed by a big rally in March. A more-ominous parallel would be back in Oct 2000 when there was a big intra-month rally to finish nearly flat. That planted a big doji on the chart but it was followed by an 8% drop the following month that continued in a two-year bear market.

SPX monthly chart