One of Wall Street's biggest bulls has just upped the ante for 2015.
Technical strategists at Piper Jaffray, which correctly foresaw much of this year's market upside, including the 's eclipse of the 2,000 mark, said the bull has more in store.
In a lengthy pair of reports sent to clients Wednesday, the firm held to its ambitious year-end target of 2,100—a nearly 6 percent gain from here—but also predicted the stock market index would hit 2,350 by the end of 2015, a 17 percent increase from the current level. That represents the highest target of any Wall Street firm and is part of a general movement to revise market hopes upward.
"We suspect that low interest rates, low inflation and dovish Fed policy will continue to underpin this equity bull market for the foreseeable future," managing director Craig W. Johnson and others said in one report. "Given there are 25 percent fewer investable stocks today than there were in the early 2000s, we think the market is primed to go higher when asset allocation shifts toward equities; this should underpin this bull market for the foreseeable future."
The research is titled "Let the good times roll" and contains nearly unfettered optimism for the times ahead, despite the headwinds the market faces.
"Investor skepticism toward this bull market remains high, and with $2.3 trillion still in money market funds, we believe there is ample dry powder still on the sidelines," Johnson wrote. "We believe the good times will continue to roll."
Piper's call comes as multiple other firms also have raised their targets.
Stifel Nicolaus is the most bullish among the rest of the pack, with a 2015 target of 2,300 it announced in August. S&P Capital IQ recently hiked its 12-month target 100 points to 2,200. Goldman Sachs has punched up its 2015 forecast, expecting the S&P 500 to register 2,150 by September of that year, and Deutsche Bank used the same 2,150 target for its year-end 2015 call.
Piper's Johnson compared the current market to the 1950 version, in which the economy was coming out of a prolonged slump, the bear market had reached a double-peak before breaking out to higher levels, and interest rates were low.
Whether the Federal Reserve is able to keep rates subdued for an extended period of time has been under debate, but Johnson thinks the slate is clear for a strong market.
"Based on history, we believe the broader market has now entered the early stages of a secular bull market that we believe still has a lot of room to run," he wrote. "In prior secular bull markets, investors made five times their money from 1952 through the mid-1960s and 15 times their money from 1982 through 1999."
—By CNBC's Jeff Cox.