Update: The photo caption on this story previously included a partial quote from Jim Cramer, it has been updated to include the full quote.

CNBC TV personality and “Mad Money” host Jim Cramer has built a lucrative career as a stock picker, but a new analysis of his charitable fund—a personal stock portfolio he co-manages that the financial website he founded has built a subscription service upon—shows he doesn’t beat the market.

Cramer’s Action Alerts Plus portfolio has underperformed the S&P 500 index SPX, -1.11% in terms of total cumulative returns since its 2001 inception, according to a working paper released Friday by Jonathan Hartley and Matthew Olson, researchers from the Wharton School at the University of Pennsylvania. While the fund outperformed the 500-member index in the years leading up to the 2008 financial crisis—which Hartley said was partially a reflection of the fund’s previous inclusion of small-cap companies and growth stocks that were outperforming during the pre-recession bull run—things have gotten worse since 2011, with Action Alerts Plus falling 9.5% in that year, when the S&P 500 was unmoved. It rose just 1.3% in 2014, versus an 11.4% increase for the S&P, the study found.

Joe Morgenstern reviews 'Money Monster'

The Wharton researchers released the report Friday to coincide with the release of the new film “Money Monster,” which stars George Clooney as a financial news host with a show similar to “Mad Money.” In the film, a less-sophisticated investor named Kyle Budwell takes Clooney’s character hostage with a bomb vest after losing all of his money because of a bad stock recommendation made on TV.

See:Jim Cramer needs to see the movie ‘Money Monster’

The Action Alerts Plus portfolio, which is used in part by Cramer and TheStreet.com to sell $15-a-month newsletter subscriptions that provide subscribers information about the fund’s holdings, its buy-and-sell strategy and exclusive market commentary from Cramer, was found to have returned 64.5% cumulatively over the past 15 years, versus 70% for the S&P 500, when adjusted for the reinvestment of dividends, according to the Wharton researchers’ study. The Vanguard Diversified Equity Fund, by comparison, a mutual fund composed of a blend of U.S.-based companies, has underperformed the S&P 500’s total return by 0.8% over the last 10 years, according to Morningstar.

The Wharton School

In addition to co-managing Action Alerts Plus, Cramer is the founder of TheStreet Inc. US:TST and one of six directors on the company’s board. He has hosted his CNBC financial show on weeknights, recommending individual stocks to buy and sell with props and loud noises, since the show’s launch in 2005.

Some of those picks have been reflected in Action Alerts Plus, such as Allergan PLC US:AGN , which Cramer has consistently recommended to viewers even as the stock has fallen 28% over the past 12 months. Allergan has a 4.57% weight in his portfolio, the second highest of all 29 portfolio companies, behind just Facebook Inc. FB, -0.89% , according to the portfolio’s holdings, which were viewed by MarketWatch and are accessible to subscribers on TheStreet.com.

Cramer told MarketWatch that he has “never promised outperformance” and that the subscription service is a “largely educational product.”

Wharton finance professor Rob Stambaugh said he didn’t think the findings in Hartley and Olson’s working paper showed significant underperformance or outperformance when taking those issues into account, and adjusting for a variety of factors. “It’s a commendable attempt to dig more deeply into the style that underlies Cramer’s stock picks,” Stambaugh said of the research.

What the Wharton analysis boils down to is that Cramer’s performance against the S&P 500 is no better than that of a vast majority of active money managers on Wall Street. A majority of active managers have underperformed their benchmarks over the last 10 years, according S&P Dow Jones Indices, though it does not provide data on the magnitude of that underperformance.

“I have nothing against Jim Cramer, have never met him, don’t have any kind of hit out on him, and I think he’s a very entertaining guy—he’s probably why I got into finance to begin with,” said Hartley. “It’s just the stock-picking thing; that’s one area you might have issue with if you look at the paper and look at the results,” he said, referencing the fund’s underperformance relative to the S&P 500.

“ There are a number of factors at play in why Action Alerts Plus has underperformed the market, including most prominently the fact that the fund keeps a large cash position so that it can donate money to charity. ”

There are a number of factors at play in why Action Alerts Plus has underperformed the market, including most prominently the fact that the fund keeps a large cash position so that it can donate money to charity, according to both the Wharton report and TheStreet. TheStreet said the fund has donated more than $2.5 million to charity since 2005 as part of the fund’s proceeds, though it does not say to which charities it allocates money. It also doesn’t reinvest dividends, which is something that can weigh on long-term market performance, though the numbers above have been adjusted for that as much as possible, according to Hartley.

Other measures that were considered in the analysis are the fund’s inclusion of companies with low quality of earnings, which Hartley said refers to companies whose earnings are based more on accruals than cash, though TheStreet, in response to that finding, told MarketWatch that there is “no universal definition” of earnings quality and that that metric is “vaguely interpreted at best.”

In the portfolio’s earliest days, it included small-cap holdings, such as the IJS Small Cap 600 ETF, which Hartley said may have played some part in the fund’s outperformance leading up to the 2008 financial crisis. Today its smallest-cap holding is in Panera Bread Co. US:PNRA , which has a market capitalization of $5 billion.

Buy-and-sell decisions for the fund, which is composed solely of Cramer’s own money, are made by both Cramer and his research director, Jack Mohr, who is employed by TheStreet.

Wharton School

Ratings for “Mad Money” and subscriptions for Action Alerts Plus, meanwhile, have been on the decline. While Nielsen’s ratings don’t account for the extent of CNBC’s daytime viewership in public places, such as offices, its in-home data through 2014 show a sharp decline in ratings for “Mad Money” since its peak in 2008—the last time Cramer’s portfolio consistently beat the S&P 500. (CNBC no longer uses Nielsen, and instead sells ads based off ratings from Cogent Reports, which declined to comment or provide ratings to MarketWatch.) CNBC also declined to comment on specific ratings.

TheStreet’s business-to-consumer subscription revenue, which includes Action Alerts Plus as well as other licenses and fees for access to securities investment information and stock-market commentary, fell 14% in its most recent quarter to $6.3 million, $1.1 million less than a year before, according to the company’s most recent earnings report. TheStreet does not break out Action Alerts Plus specifically, but it did blame the division’s sales slide on declines in both the number of overall subscribers and the amount of revenue made per subscription, the company said. In its most recent 10Q, filed with the Securities and Exchange Commission, it said that the decline in business-to-consumer revenue was primarily related to TheStreet newsletter products.

The business had 71,900 total paid subscribers as of March 31, which, a source close to the matter said, primarily comprises Action Alerts Plus subscribers. That is a decrease of 11,700, or 14%, from the year-earlier period. Nearly 5,000 of those dropouts, 4,900, have occurred since the end of 2015. TheStreet declined to comment on the loss in subscribers.

Shares of TheStreet US:TST have declined nearly 40% over the past year and are now trading at around $1.10 a share.