Today: Three Silicon Valley companies are preparing to go public next week, ahead of a massively anticipated offering from Twitter. Also: Intel (INTC) rises, Apple (AAPL) and social stocks decline.

The Lead: FireEye, Rocket Fuel and Five Prime ready for market debut

With the financial community abuzz from Twitter's Thursday announcement of plans for an initial public offering, three Silicon Valley companies are expected to make their debuts next week, offering the San Francisco microblogging stalwart a temperature check of the IPO market.

Milpitas security software company FireEye, Redwood City advertising-technology company Rocket Fuel and South San Francisco biotech company Five Prime Thearapeutics are expected to price their initial batch of shares and debut on Wall Street next week, Renaissance Capital reported Friday. If the companies go through with their expected IPOs, the three companies will be the first of a wave of expected Silicon Valley market debuts: Seven Bay Area companies, including those three,