The S&P 500 has gained 15.7 percent this year, led by mostly defensive plays in health care, consumer stocks and financial sectors.
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Lee said the firm expects technology to join health care and financials as market leaders.
After slogging through the post-financial crisis years and sitting out a good portion of a 140 percent rally, retail investors have begun putting cash to work in equities.
Data from Lipper and the Investment Company Institute have reflected money flowing into stocks, though bonds continue to attract cash as well.
For the most recent reporting period, equity and bond funds both took in $3.1 billion, according to Lipper, as investors continued to defy predictions for a "Great Rotation" of money from stocks to fixed income.
Yet for all the rallying and bullish calls, signs of upside capitulation—the point at which optimism hits a peak and signals a selloff—are elusive.
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The latest American Association of Individual Investors survey shows the bulls and bears right around historical norms, with 38.5 percent expecting the market to rise and 29.3 percent predicting a decline.
JPMorgan's bullish call is based on a belief that the economy will continue to improve, a view that comes in the face of data showing weakness in employment, manufacturing and even a slowdown in housing.
Lee points to market performance of semiconductors and transport stocks, as well as the steepening of the yield curve. Indeed, Dow transports, considered a bellwether for economic prospects, have surged nearly 22 percent in 2013, far outpacing broader market growth.
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"In our view, these historically have been reliable market indicators of improving growth," Lee said.
The outlook is even more optimistic than Piper Jaffray's call for a 1,700 on the S&P 500, or S&P Capital IQ's target of 1,670.
As for risks, Lee said the biggest obstacle would be the market losing faith in its chief benefactor—the Federal Reserve.
The Fed has been buying $85 billion a month in Treasurys and mortgage-backed securities, and the liquidity has been widely credited for boosting equity prices even if it has been less successful in creating demand that would lead to economic growth.
_ By CNBC's Jeff Cox. Follow him on Twitter @JeffCoxCNBCcom.