The nine-year-old bull stock market may be running out of wind, according to some investment gurus.

“It’s been almost too good,” said Jim Paulsen, chief investment strategist at the Leuthold Group, who was one of the early believers in the 2009 market rally from the depths of the Great Recession.

“And when things have been too good in the market, it can take just one bad item …,” Paulsen said. “I don’t see a bear market because we’re nowhere near a recession. But most of the good things are already priced into the market.”

The Standard & Poor’s 500 stock index is up about 20 percent this year. Moreover, the total return of the S&P 500, including reinvested dividends, is 18 percent compounded annually since March 2009.

The S&P 500 index peaked in 2007 at about 1,550, several months ahead of the market collapse and 2008-09 recession.

It crossed 1,550 and into record territory again in 2013, as the economy, employment and confidence returned to the United States after the job-and-wealth scorching recession. The market soared above 2,600 in November, amid continued low unemployment, record corporate profits, recent-quarter economic growth and low inflation and interest rates.

The stock market has been a good place to make money for eight years.

Investors who shunned the market when it was ailing-to-climbing early in the halting economic recovery have come back in droves. Many now-exuberant investors believe that 3 percent economic growth will improve earnings and stock prices.

“Perhaps we are in the early stages of [another] ‘melt up’ similar to the late stages of past bull markets,” Paulsen told clients this month. “However, several … indicators are on the cusp of eye-catching levels that could shatter the ‘sweet-spot’ scenario.”

Paulsen believes that the stock market run could be deterred by several variables that all end up at about 3 percent.

First, low unemployment, down to around 3 percent in some places, including the Twin Cities area, has meant employers are paying up for workers, adding some wage inflation. Good for workers, who are finally getting decent raises. Wages are heading toward 3 percent growth for the first time since 2009, according to Leuthold research.

Also Paulsen points to recent growth in the consumer price index, as well as higher fourth-quarter oil prices. This also points toward 3 percent consumer-price growth. The 10-year U.S. Treasury bond also seems headed toward 3 percent for the first time in years. This could start to kindle an inflationary outlook. That typically dampens the outlook for the stock market. And market skeptics, such as Paulsen, say the S&P 500 is already pricing in good future earnings and a rosy economic outlook.

Finally, Paulsen believes that the tax plan taking shape in Congress is a badly designed economic-stimulus plan built more around Republican politics than relief that targets the working and middle classes. Assuming the House and Senate versions can be melded into one bill and passed, it also could mean an additional $1 trillion-plus in federal deficits, at a time when the economy is already humming.

In short, the tax plan could overheat a hot economy.

“There is no economic rationale to it,” said Paulsen, 58, an economist out of Iowa State University who spent 25 years as a market strategist at Wells Fargo Capital. “They should pass something and bring it out when there’s a recession. Maybe it will get watered down enough so it won’t matter [after House-Senate conference committee deliberations set for this week].

“The bigger point is that this market recovery was built on a ‘wall of worry’ since 2009,” Paulsen said. “Now the feelings are comfort and optimism, confidence. We’re at the first time in the recovery when the ‘water is safe.’ ”

And when investors get too confident, that’s often when the stock market goes sideways or slips. Indeed, the market has been choppy in December, amid year-end profit taking and some doubts.

Mark Henneman, the veteran chief investment officer at investment manager Mairs and Power of St. Paul, is a little more sanguine than Paulsen.

Henneman, a buy-and-hold investor, oversees one of America’s best-performing mutual funds, the Minnesota-dominated Mairs and Power Growth Fund. He doesn’t think we’re in a danger zone, and he doesn’t think the market is going to add too much following the roaring 2015-16 period. It may back off a bit but not crack. We’re in a good economy, he said, with companies he owns producing a growing stream of earnings.

The U.S. economy and stock market bloomed after European countries stimulated their economies so the U.S. wasn’t growing alone. U.S. companies with international exposure benefited. Meanwhile, China’s economy is recovering.

Investment strategists at Bank of America Merrill Lynch wrote last week that the bull market may be waning.

The market is not at risk of any type of 2008 collapse, say analysts such as Paulsen and Henneman, thanks in part to the regulatory response to the crisis, stronger surviving banks and the federal bailout of the financial sector in 2009-11 that transferred hundreds of billions of underperforming mortgages and other bad assets to the Federal Reserve. Many surviving institutions were able “de-leverage” balance sheets and recover.

However, we could witness a down swoon of 10 percent, not a surprising breather amid a bull of this length, if some of what Paulsen worries about occurs, or if there’s geopolitical trouble in the Middle East or the Korean Peninsula.

Scott Anderson, chief economist at Bank of the West, ticked off a list of positive attributes earlier this month, including U.S. business-equipment spending that grew 10 percent last quarter.

He concluded a note to investors: “Fourth quarter GDP growth appears likely to remain above trend at around 2.5 percent. But maintaining this outperformance into 2018 will be extremely difficult. We expect growth to slow to just over 2 percent next year. And we see plenty of risks, from overvalued stocks, an overextended consumer, a [federal] debt-ceiling deadline, geopolitical tensions, tighter monetary policy and rising interest rates.

“For now, let’s enjoy the year-end party.”