A simple yet powerful technical indicator is flashing a red warning light that stocks are overheated:

Click to enlarge

SPY_-_NYMO

NYSE McClellan Oscillator (ratio adjusted) with S&P 500 above

80.30 is the highest the NYSE McClellan Oscilator has read since September 18th, 2013, a date which marked a short term market top from which the S&P pulled back roughly 4% over the ensuing weeks. The fact that the VIX has also fallen back to important 'support' near 14 makes this an enticing shorting opportunity for US equities.