When all of the available share classes are taken into account, the mutual fund universe comprises over 26,000 offerings. Needless to say, it can be tough for a fund and its manager to stand out from the crowd, a key to attracting assets. Although performance goes a long way to setting a fund apart from the pack, this quandary might explain the wide range of oddball funds in the marketplace.

Managers have little to lose by throwing ideas at the wall; the worst case scenario is that they fold up shop and live to launch another fund on another day. As is often the case, investors taken in by slick sales gimmicks have the most to lose if the manager’s idea doesn’t pan out.

For illustrative purposes–and in the spirit of April Fools’ Day–here are three real mutual funds that beg the question, “What were they thinking?”

The Congressional Effect Fund (CEFFX) is the brainchild of Eric Singer, an analyst who did extensive research in the early 1990s on how Congress affects the stock markets. Not surprisingly, he concluded that about all Congress was good at was creating uncertainty–something every investor knows the markets hates.

The Congressional Effect Fund, the logical conclusion of Singer’s research, launched in mid-2008. Deciding that it was best to be in the markets when Congress was out of session, Singer invests the fund in SPDR S&P 500 (NYSE: SPY), e-mini S&P 500 contracts and futures when the legislature adjourns. When Congress is sitting, the fund holds Treasury bills and other short-maturity government debt obligations.

The fund got off to an auspicious start, outperforming in the last half of 2008 after avoiding the worst of the S&P 500’s plunge. But the shine came off last year; having sat out the market’s rally, the fund ranked at the bottom of Morningstar’s Moderate Allocation category.

Although Singer’s data backs up his thesis that Congress has an extremely negative effect on the market, investors aren’t likely to come out ahead with the fund.

The Constitution mandates only that Congress meet once a year, and the body itself determines how many days out of the year it works. Since that document was penned, governing the country has become a fulltime job; Congress is typically in session about eight months out of the year, leaving little time for the fund to be in the market. It would take years for the fund to generate a tangible benefit from avoiding the so-called Congressional effect.

On top of that, the fund’s expense ratio currently runs 1.87 percent per year, though Singer has agreed to limit expenses to 1.75 percent of assets through at least July. Even with that concession, the fund is extraordinarily expensive. High expenses, coupled with the fund’s esoteric investment thesis, have prevented it from accumulating much in the way of assets under management.

Because I can’t think of a better gauge of Congressional performance than the government debt market, it strikes me as odd that the fund would invest in government debt when legislators are in session. Gold stocks would make much more sense to me.

StockCar Stocks Index (SCARX) is an unusual fund that seeks to ride the coattails of what is rapidly replacing baseball as the national pastime–car racing. The fund tracks an index composed of 40 companies that sponsor NASCAR’s Sprint Cup Racing Series.

Try as I might, I haven’t been able to come up with any compelling reason why an investor should sink money into this fund.

The charitable assessment is that the fund is attempting to capitalize on the boost in sales a company might enjoy when it sponsors a car on the NASCAR circuit. But that’s a tough effect to quantify, particularly because most sponsors are large-cap companies. In reality, this investment thesis is most likely just a gimmick.

Alliteration aside, StockCar Stocks Index is a large-value fund with a costly expense ratio of 1.5 percent. And with just $4.2 million in assets, it’s a deservedly tiny fund. Apparently, NASCAR mania only goes so far.

It also appears that the fund may soon be taking the cut-and-run approach; its website has disappeared and attempts to contact management proved fruitless.

As the name implies, Marketocracy Masters Fund (MOFQX) seeks to democratize the investment process by bringing high-quality information and successful investment strategies to the public’s attention.

The firm also aspires to develop investment talent, regardless of whether that’s you, me or an analyst on Wall Street. To that end, anyone can create and manage a simulated mutual fund on the website, http://www.marketocracy.com.

Trade data on the top 100 performers’ portfolios is provided to the fund’s managers, who then choose what they consider to be the best ideas of the bunch.

That’s certainly a novel approach, and it’s gratifying that the fund acknowledges that working on Wall Street doesn’t make someone any more qualified to run a portfolio.

Unfortunately, that feel-good thesis doesn’t amount to better performance. On a one-, three- and five-year basis the fund ranks near the bottom of its Morningstar category–currently,

Mid-Cap Blend. But because the fund doesn’t adhere to any particular style, it’s impossible to pigeonhole.

Regardless, the fund’s performance isn’t impressive and expenses are extremely high. It’s tough to see how the fund’s situation could improve in coming years.

Unfortunately for these funds–and their investors–they can’t just throw up their hands and shout, “April Fools!”