So long as Washington doesn't flub a solution to the nation's fiscal problems, the S&P 500 should log a 13 percent gain in 2013, Citigroup's chief U.S. equity strategist, Tobias Levkovich, told CNBC's "Squawk on the Street" on Monday.
"If all we're doing is going past December 31 and have to do something in the first couple of weeks in January, I don't think it rips apart the opportunity for next year," said the strategist on the timing for a potential deal to avert the "fiscal cliff" of automatic tax hikes and spending cuts.