On Thursday, the Wall Street Journal reported that the Securities and Exchange Commission is expected to approve new regulations for money-market mutual funds. Remember money-market funds? Before the financial crisis, these funds were very popular places to stash money because each share was expected to maintain $1 value. Your principal would remain the same, and the fund would pay substantially higher interest rates than a bank savings account. But these days for retail investors, money-market mutual funds are something of an afterthought. So why is the SEC intent on regulating them now? And will tighter rules push them further into irrelevance? Here’s what you need to know: What going on? A money-market fund is a mutual fund that’s required by law to invest only in low-risk securities. (Don’t confuse funds with money-market accounts at FDIC-insured banks. These rules don’t affect those.) There are different kinds of money-market funds. Some are aimed at retail investors. So-called prime institutional funds, on the other hand, are higher-yielding products used by companies and large investors to stash their cash. The big news in the proposed rules affects just the prime institutional funds. Prime institutional funds would have to let their share price float with the market, effectively removing the $1 share price expectation. The SEC reportedly also wants to impose restrictions preventing investors from pulling their money out of these funds during times of instability, or discouraging them from doing so by charging a withdrawal fee. It’s unclear from the reporting so far which kinds of funds this would affect. Why is the SEC doing this? As MONEY’s Penelope Wang wrote in 2012 when rumors of new regulations were first circulating, the financial crisis revealed serious vulnerabilities to money-market funds. When shares in a $62 billion fund fell under $1 in 2008, it triggered a run on money markets. In order to stabilize the funds, Washington was forced to step in and offer FDIC insurance (the same insurance that protects your bank account). That insurance ran out in 2009, and now the funds are once again unprotected against another run. The majority of the SEC believes a primary way to prevent future panics is to remind investors that money-market funds are not the same as an FDIC-insured money-market account at a bank. Before the crisis, the funds seemed like a can’t-lose proposition. The safety of a savings account with double the return? Sign me up. But as investors learned, you actually can lose. What does it mean for you? Not much, at least not right away. The floating rate rules only apply to prime institutional funds, which the Wall Street Journal says make up about 37% of the industry. The change also won’t be very important until money-market funds look more attractive than they do today. Historically low interest rates from the Federal Reserve have actually made conventional savings accounts a more lucrative place to deposit money than money-market funds. The average money-market fund returns 0.01% interest according to iMoney.net. That’s slightly less than a checking account. Investors have already responded to money funds’ poor value proposition by pulling their money out. In August of 2008, iMoney shows there was $758.3 billion invested in prime money fund assets. In March of 2014, that number had gone down to $497.3 billion. Finally, it appears unlikely that money-market funds will ever be as desirable as they were pre-crisis. As the WSJ’s Andrew Ackerman points out, money funds previously offered high returns, $1-to-$1 security, and liquidity. Interest rates have killed the returns, and the new regulations will limit liquidity and kill the dollar-for-dollar promise. Don’t count the lobbyists out yet Fund companies are really, really unhappy about the SEC’s proposed regulations. They’ve been fighting the rules for years, and until there’s an official announcement, you shouldn’t be sure anything is actually going to happen. Others are worried the new regulations, specifically redemption restrictions, might actually cause runs on the market as investors fear they could be prevented from pulling money out if things get worse. But the SEC may have picked a perfect time to do this. With rates so low, few retail savers care much about money-market funds. That wasn’t true back when yields were richer and any new regulation of money-market funds might have been met with a hue and cry from middle-class savers. Today? Crickets.