An official bear market is a 20% decline in the stock market. By that definition, stocks didn’t encounter a bear market in the first quarter. It sure felt like it, though. The Standard & Poor’s 500-stock index fell 9.4% during the first quarter, even when you include reinvested dividends. By the end of the third quarter, the blue-chip index had tumbled 15.5% from its Oct. 9 all-time high.

Painful as a down market is, it’s all too easy to magnify the misery. Here are five common errors that can make it even worse:

1. Timing the market.

We’d all love to get out of the stock market at the top and in at the bottom. But academic studies have long shown that market timing is almost always futile.

Many timers use a 200-day average stock price as a market-timing tool; they sell once a fund’s price dips below its average price and buy when it rises above that average.

In the past 12 months, the S&P 500 which, by historical standards, was highly volatile during that period crossed its 200-day average price 10 times. But don’t try to time the highs and lows. Frequent trading racks up transaction costs. If you’re in a taxable account, your short-term capital gains unlike long-term gains are taxed at the same higher rate as ordinary income.

2. Panicking.

It rarely pays to sell when everyone else does. Consider the market meltdown on Feb. 5, when the S&P 500 shed 44 points for a huge 3.2% loss. As a mutual fund shareholder, you would have sold at the fund’s price by the end of the day. As a result, you would have locked in your 3.2% loss.

Typically, the market rallies a bit after a sharp decline. If you avoid selling and just wait awhile, you can often recoup some of your (paper) losses. In this real-life example, you’d have regained your entire investment, and a bit more, by Feb. 26. If you’re investing for a long-term goal, such as retirement, take a deep breath and remember: This, too, shall pass.

3. Using high-cost funds.

It’s bad enough to lose money in a bear market. But the more you pay your fund company, the more money you’ll lose once the market turns south.

You can find a fund’s expense ratio in its prospectus. Or, armed with your fund’s ticker symbol, you can find it on USA TODAY’s website at money.usatoday.com.

4. Turning to bear funds.

Some funds are designed to rise when the stock market falls, which is beneficial in a bear market.

Problem is, these funds are also designed to fall when the stock market rises. And the stock market rises more often than it falls. (The average bear market lasts 382 days, according to the Stock Trader’s Almanac. while the average bull market lasts 721 days.) Unless you sell your bear-market fund in time, it’ll eventually be a drag on your portfolio.

5. Quitting.

It’s discouraging to lose money. But the biggest single factor in your success as an investor is how much you save not how much return the stock market gives you. If you fear that you’re not going to meet your investment goals, your best remedy is saving more.