US STOCKS-Wall St rises; Internet, biotech names lift Nasdaq
* Internet names rally; concerns remain over valuation
* AT&T to buy DirecTV for $48.5 billion
* Russell 2000 rebounds after three-day decline
* Dow up 0.1 pct; S&P 500 up 0.4 pct; Nasdaq up 0.9 pct (Updates to close)
By Ryan Vlastelica
NEW YORK, May 19 (Reuters) - U.S. stocks rose on Monday, with a rally in high-growth names among Internet and biotech shares giving the Nasdaq a gain of almost 1 percent.
Equities have been pressured recently, with the S&P 500 coming off its first two-week decline since January as investors have become concerned about the economy's growth prospects.
"The listlessness in the market shows the struggle investors are having right now: Valuations are full but not stretched, and there's a lack of decisive evidence that the economy will kick into higher growth and justify these valuations," said Mark Luschini, chief investment strategist at Janney Montgomery Scott in Philadelphia.
High-growth "momentum" stocks were among the strongest of the day, with TripAdvisor Inc up 5.2 percent at $86.41 and Netflix Inc up 4.2 percent at $364.50. Vertex Pharma gained 3.4 percent to $67.22. Continuación...