US STOCKS-Wall St rises on gains in healthcare stocks; Fed eyed
* Fed Chair Yellen to speak at 2:00 p.m. ET Wednesday
* Tobira Therapeutics rises eight-fold on Allergan deal
* DTS soars on $850 mln acquisition agreement with Tessera
* Indexes up: Dow 0.31 pct, S&P 0.24 pct, Nasdaq 0.22 pct (Updates to early afternoon)
By Yashaswini Swamynathan
Sept 20 (Reuters) - Wall Street was higher on Tuesday afternoon, helped by gains in healthcare stocks and an overall sentiment that the U.S. Federal Reserve might not raise interest rates.
Though the Fed is not expected to raise rates in a two-day meeting, Chair Janet Yellen's speech on Wednesday is keenly awaited for any clues about rate changes in the coming months.
Traders have priced in a mere 18 percent chance for a rate hike by Wednesday, according to The CME Group's FedWatch tool.
Investors are also keeping an eye on the Bank of Japan's policy meeting that ends on Wednesday. Continuación...