A second week of tech stock selloffs and the flop of the "Candy Crush" IPO showed Wall Street now wants more concrete reasons to bid up stocks after a five-year bull run. Blue chips stocks, as measured by the Dow Jones Industrial Average, barely held up in the week to Friday, and the broader S&P 500 only took a minor loss. But huge volatility came with some real selling that reflected worries about the Ukraine crisis, still sluggish US growth, as well as the sagging Chinese economy. And while the Federal Reserve's repeated assurances of ultra-low interest rates well into 2015 has kept investors liquid, it is increasingly clear that they want to see more growth and earnings from companies before chasing their shares higher. The Dow ended the week with a 0.12 percent gain, to 16,323.06. The S&P 500 fell 0.8 percent to 1,857.62. But the Nasdaq Composite Index, more populated with technology listings, lost 2.8 percent for the period. The severity of the tech selloff was masked by small gains by giants Microsoft and Apple. Beyond them, it was mostly losses. Google fell 5.3 percent, Amazon 6.2 percent, Yahoo 5.4 percent, Yelp 8.4 percent, Facebook 10.8 percent, Twitter 7.1 percent, and Netflix 11.6 percent. And Tesla, the electric car maker being treated as a tech startup, finished the week 7.2 percent lower. Sectorally, biotechnology was hit particularly hard. Nasdaq's biotech index lost 2.8 percent Friday and 7.0 percent for the week. Gilead Sciences gave up 4.9 percent in the period, and Biogen Idec was down 7.7 percent. As if to underscore that message of nervousness about overvaluation in tech, King Digital, the maker of the addictive game mobile Candy Crush, was the week's big IPO and its big flop. The company's shares were subscribed at $22.50, valuing the so far one-hit-wonder at $7.1 billion. But they sank immediately upon hitting the market Wednesday and ended the week off nearly 20 percent at $18.08. "The market is going through a correction underneath the surface," said Tom Cahill of Ventura Wealth Management. "When you look at the S&P 500, it is down just a little bit from its all-time intraday high." "But underneath, quite a number of companies have actually started to correct. In the Russel 1000 index, more than half are down more than 5 percent," he added. Cahill said the losses are not a bad thing. It mainly means that investors are tilting away from the high-growth, high price-earnings ratio companies. Instead, they "are looking for a home somewhere else that is a little more safe." "Clearly this not 2013," said Michael Gayed of Pension Partners. "This is somewhat of a shock for some investors. Investors to some extent are questioning valuation, especially on the small caps." He said there is also nervousness about overshooting valuations as the first quarter earnings season approaches.