Key TakeawaysEnphase Energy shares slumped more than 8% in premarket trading Wednesday after the solar solutions maker missed analysts' Q1 earnings and sales estimates, and issued a soft current-quarter sales outlook.The company said a further softening of the U.S. solar market, along with seasonality factors and a reduction in shipping, weighed on revenue in the quarter.A close below last week's low at $105.61 could see a continuation of the long-term downtrend in Enphase shares. Enphase Energy (ENPH) rele ...