Tech stocks lead losses as US indices pull back from rally

Brendan McDermid/ReutersUS stocks were lower on Tuesday after Monday's rally led to valuation concerns.SEC nominee Gary Gensler said he would look to ensure retail investors get "best execution" for their trades.China's banking regulator warned US markets are potentially creating bubbles. Sign up here for our daily newsletter, 10 Things Before the Opening Bell.US stocks were lower on Tuesday with tech stocks leading losses in the Nasdaq and S&P 500 after a strong rally on Monday led inv