An indicator with a perfect track record just sent a 'powerful' sell signal
Investors poured $33.2 billion into stock-based funds last week, another indication that the market may be overheating.
Bank of America Merrill Lynch's "Bull & Bear" indicator is sending a sell sign, which has been accurate 11 straight times since the firm started tracking it in 2002.
The indicator points to a technical pullback for the S&P 500 to 2,686, which would be about a 6 percent drop from the current level.