* Wall Street coming off worst week of 2013
* Halliburton rallies in premarket after results
* Power-One soars after $1 billion purchase offer from ABB
* Futures up: Dow 65 pts, S&P 7.4 pts, Nasdaq 17 pts
By Ryan Vlastelica
NEW YORK, April 22 U.S. stock index futures were higher on Monday, rebounding from stocks' worst week 2013, as the latest quarterly earnings included major companies ranging from Caterpillar Inc to Halliburton Co to Texas Instruments Inc.
* Wall Street is coming off a week of extreme volatility, with the CBOE Volatility index jumping 24 percent, the biggest weekly gain for the so-called fear index this year.
* The swings were largely driven by weak corporate earnings and signs of slowing growth from China, which contributed to a precipitous drop in commodity prices. The week's decline fueled talk that the market's long-awaited pullback had arrived, though the S&P remains up 9 percent on the year.
* However, equities rose on Friday, and the follow-through implied by Monday's futures suggested that investors may still use market weakness as a buying opportunity.
* Caterpillar reported results early Monday, and shares dipped 0.1 percent to $80.35 in premarket trading. Halliburton rose 4.8 percent to $39.01 in premarket trading after posting its results.
* Earnings also due on Monday included Texas Instruments and Netflix Inc.
* With 91 S&P 500 components having reported, 70 percent of companies have topped profit expectations, according to Thomson Reuters data. Analysts expect earnings growth of 2.1 percent this quarter, up from expectations of 1.5 percent at the start of the month.
* S&P 500 futures rose 7.4 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures added 65 points and Nasdaq 100 futures rose 17 points.
* Investors will be looking to the S&P 500's 50-day moving average of 1,543.9, which could serve as a level of market support. The index closed under that level for the first time this year on Thursday but rebounded above it on Friday.
* Power-One Inc soared 56 percent to $6.29 in premarket trading after ABB agreed to buy the company for about $1 billion.
* Overseas, European shares rose 0.8 percent, lifted by signs of political progress in Italy following the re-election of the country's president.
* U.S. stocks mostly rose on Friday, boosted by strong results from Google Inc and Microsoft Corp. However, the Dow was severely pressured by weakness in IBM , McDonald's and General Electric Co, all of which reported earnings that disappointed investors.