NEW YORK (CNN/Money) - Following regulators' allegations of securities fraud at Putnam Investments, the nation's fifth largest mutual fund company, several state and city pensions have fired the firm and some individual investors have taken their money elsewhere.

As a result, the company has lost about $30 billion in assets -- or about 11 percent of total assets under management -- since Oct. 31.

That raises a question for all investors who own mutual funds that may be charged with improper trading: If investors start packing up their tents in your fund, should you follow suit?

So far, there hasn't been much evidence of an investor exodus. But given the speed at which the fund scandal is unraveling, it may become a relevant question for some investors in the coming months.

If there's evidence of a mass exodus from your fund, you don't want to be the one left holding the bag.

Here's why: When there are large-scale redemptions from a mutual fund, the managers are forced to sell investments that they might otherwise have chosen to hold, incurring capital gains (and a bigger tax bill) for the investors left behind as well as higher transaction costs for remaining shareholders.

It's a case of "Last man out, turn out the lights, please," said certified financial planner Rick Applegate.

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What's more, the push to sell investments to meet redemptions might tamper with the fund's asset allocation, Applegate said. And the imperative to raise cash may distract the fund manager from doing his main job, which is investing with an eye toward good returns, said Morningstar fund analyst Laura Pavlenko Lutton.

The expense ratio for owning your fund is also likely to increase over time when the assets under management fall, since the fixed costs for running the fund haven't fallen along with them.

For example, if it costs $1 to run a fund and a fund's assets drop from $100 to $90 because of a rash of redemptions, what used to be a 1 percent expense ratio ($1 is 1 percent of $100) will increase to 1.11 percent ($1 is 1.11 percent of $90), said Chris Wloszczyna, a spokesman for the Investment Company Institute, the mutual fund industry trade group.

And the fund company also may ask the board of directors and shareholders to raise the management fee -- which is part of the expense ratio.

While there may be increased costs to the remaining shareholders when there are a lot of redemptions, the tax bite isn't an issue if you're invested in those funds through a 401(k) or other tax-deferred, qualified plans. It's a much bigger concern if your exposure to the fund is in a taxable account, Applegate noted.

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Keep in mind, though, even if you're in a taxable account and your fund invests in growth stocks, the manager may have a lot of capital losses left over from the bear market that he or she can use to offset capital gains incurred as a result of sales made to meet redemptions, Lutton said.

Also, if you have exposure to a fund family but not in the funds that have experienced the large redemptions, you may not be affected. (Much will depend on whether the fund complex raises expenses across the board or just in the funds affected by investor withdrawals.)

You also don't want to be quick to sell all at once if by selling you'll incur a huge capital gains tax. The cost is twofold, especially if your investment was earmarked for long-term goals: first, you'll have a big tax bill to pay for the current tax year; and second, paying the tax now reduces the amount of investment money left to compound for you over time. (Again, this is only an issue if you're in taxable account.)

Applegate's advice? If, absent the scandal, the funds you're in still live up to the reasons you invested in them (solid long-term performance, low fees and tax efficiency as well as a good fit in your asset allocation, among others) "then I wouldn't be one to quickly make changes," he said. But he noted that he'd monitor it very closely and leave the fund if it continues to make headlines.

But even if your fund hasn't experienced big redemptions, if you have the bulk of your investments with one fund family and that fund family is being investigated, you should consider moving some of your holdings to another fund family just as a prudent measure, Lutton said.

Mutual fund scandals have many investors wondering what to do with their money. CNNfn's Allan Chernoff reports on some recommendations. Play video (Real or Windows Media)

If one of your funds comes under fire, and you want to keep track of whether investors are holding the line, said certified financial planner Tom Gryzmala, call your fund company and ask to get three sets of figures both for Sept. 3 (when the mutual fund scandal first came to light) and today: daily volume trade, assets under management and your expense ratio.

If in that period, daily trades and the expense ratio are up significantly and assets under management are down (say 10 percent or more), that's a sign that other investors are pulling money out of the fund, and is a sign you, too, should sell, he said.