In the last eight quarters, the S&P is up 46 percent. That's the longest and strongest winning feat since 1998, when the market rose 147 percent over a stretch of 3 ½ years (From Q1 1995 to Q2 1998, the S&P posted 14 quarters of gains).
Read MoreThese are the winners of the S&P rally
The current winning streak is certainly unusual and has taken place only three other times in history. Apart from 1998, stocks rose 57 percent back in 1965 over a stretch of eleven quarters (From Q3 1962 to Q1 1965), and then in 1956, when the market was up 108 percent during 10 quarters of gains (From Q4 1953 to Q1 1956).
Despite the solid gains in the recent years, Wall Street believes there's further room to run. According to CNBC's Strategist Survey, the average S&P target price for 2015 stands at 2,220, implying a 6.5 percent increase from the current levels.