Mining trucks and machinery operate in the Fimiston Open Pit, known as the Super Pit, in Kalgoorlie, Australia. (Bloomberg via Getty Images, Getty)

Many major gold companies have lost at least half their value this year after a more than 25 percent plunge in gold prices, but analysts aren't convinced that miners have hit bottom -- and tax-loss selling may further the declines.

The Philadelphia Gold and Silver Index (XAU) has lost 50 percent year to date and the NYSE Arca Gold Bugs Index (HUI) has declined 56 percent. Shares of Barrick Gold (ABX), the world's largest gold-mining company, have dropped by 51 percent this year.

Among exchanged-traded funds, the Market Vectors Gold Miners (GDX), which provides exposure to publicly-traded companies involved primarily in gold mining, sank this month to its lowest level in about five years. It's down 55 percent this year.

The losses for the gold miners aren't much of a surprise given the hefty declines in gold prices, which are poised to log their first loss in 13 years. But shares of the gold miners have suffered a drop that's roughly double the year's price loss for the metal.

"Gold stocks have actually been underperforming gold since the 2008 credit crisis," said Brien Lundin, editor of Gold Newsletter.

"That's because the U.S. and global economies have bounced from crisis to crisis," he said. "And "in times of great financial uncertainty, investors buy gold as insurance and don't want to take on the added risk of paper equities."

But as gold prices and mining shares lost favor, U.S. stocks gained. The S&P 500 Index ($INX) has climbed 25 percent this year.

"Many investors have large gains in their portfolios because domestic stocks have excelled," said Malcolm Gissen, co-manager of the Encompass Fund (ENCPX). "With markets near all-time highs, some investors are balancing portfolios and realizing significant capital gains."

And "what in their portfolios have declined to offset the gains? Gold stocks," said Gissen. "The miners are suffering largely because of tax-loss selling."

Not yet a bargain

Still, given the plunge in so-called paper gold, investors can't help but wonder whether it's a bargain now. It isn't -- at least, not yet, according to some analysts.

"Gold gurus and actively-managed gold mutual funds have been pounding the table all year saying gold was near a bottom and we should be buying, especially the gold stocks," said Gissen. "They have been wrong." (Read what analysts were saying in May about gold and silver mining shares.)

Gissen said The Encompass Fund and investment advisor Malcolm H. Gissen & Associates, which he founded, sold almost all gold stocks early this year and "have not bought a single gold stock in 2013."

He said "2014 will also be a difficult year for gold and gold stocks, and it is unlikely we will be a buyer."

At some point the Federal Reserve will start to taper its bond-buying program and then at some point in the next 2 to 3 years, he expects gold prices to rise and the gold stocks to soar -- "the fundamentals are too strong for this to not happen."

"If an investor has a strong stomach and patience, he could buy a number of gold stocks in here, hold them for 3 to 5 years, and would likely make a lot of money," he said, but "what investors have patience anymore?"

Finding 'survivors'

So for now, analysts were reluctant to say miners have hit bottom.

"There's really no bottom in sight right now, unfortunately, and there are a lot better opportunities in other areas of the markets at this point," said Adam Koos, president of Libertas Wealth Management Group.

"Bullish percent for mining equities currently sits at 14 percent and falling -- meaning that only 14 percent of all mining stocks are on a buy signal" versus 86 percent on a sell signal, he said.

But there were a few suggestions for potential winners among the miners in the new year.

"The survivors in the (mining) spacer are going to be the companies with solid balance sheets, meaning they are not levered and who can deliver on guidance at a decreasing cost metric in the current environment," said Jeffrey Wright, managing director at H.C. Wainwright LLC.

He believes the winners in relative terms "have been or are in the process of adjusting the reigning in labor, material and exploration expenses while either increasing production or meeting guidance targets." He favors silver over gold in the near-to-medium term because of the potential for a more robust U.S. economic recovery.

And going into 2014, Wright likes small cap companies such as Great Panther Silver (GPL) which has multiple silver and gold mines in Mexico with a low-cost satellite mine going into production early in the new year. The company has a large cash balance and no debt, he said, while Comstock Mining (LODE) has a gold and silver open pit mine in Nevada and should surpass guidance for 2013. He doesn't hold any positions in those stocks.

As for Gissen, even though his firms sold almost all gold stocks early this year, he said investors with patience should be buying producers with growing production and lots of resources.

Among the larger producers, those would be Goldcorp (GG) and Yamana Gold (AUY) which look undervalued and should be expanding production over the next few years, said Gissen, who owns stock in the companies he mentioned.

Cary Pinkowski, chief executive officer of gold miner Astur Gold (ATRGF), said he would encourage buying quality gold producers like Osisko Mining (OSKFF) which has "life of mine energy costs locked in." He also pointed out that Angico Eagle Mines (AEM) just hit another record quarter of production. The company has "held up very well and these are usually the first to turn."

"When you buy in markets like this, expect them to go lower but when they turn, these stocks can really move to the upside," Pinkowski said.

Click here to become a fan of MSN Money on Facebook

More from MarketWatch: