May 4 Reuters The Nasdaq index was set to open lower on Tuesday as investors continued to move out of megacap growth stocks and into companies that are expected to benefit from the reopening of economies.

Highly valued technology companies including Microsoft Corp , Alphabet Inc, Apple Inc, Amazon.com Inc and Facebook Inc fell between 0.6 and 1.7 in premarket trading.

U.S. and European stock markets also saw a sudden 0.5 drop in hefty volumes around 730 a.m. ET on Tuesday, leaving traders scratching their heads and one calling it a micro flash crash.

Copious stimulus measures, speedy vaccination drives and the Federal Reserves accommodative policy stance have spurred a strong rebound in the U.S. economy and pushed Wall Street to record highs this year. The socalled pandemic winners, however, have recently started to fall out of favor.

While megacap tech companies have been a core part of the solid performance of portfolios throughout the pandemic, we think investors should be careful to avoid overallocation to this part of the market, Mark Haefele, chief investment officer at UBS Global Wealth Management, wrote in a client note.

In an environment of accelerating growth, we continue to prefer cyclical and value sectors such as financials and energy.

Planemaker Boeing Co rose 0.2, while oil major Chevron Corp gained 0.7.

At 838 a.m. ET, Dow eminis were down 136 points, or 0.4, SP 500 eminis were down 22.25 points, or 0.53, and Nasdaq 100 eminis were down 113…