(Bloomberg News) Wal-Mart Stores Inc. is the new gold.

The world's largest retailer is attracting investors who see its shares as a safe haven amid a slowing global economy and volatile growth stocks. With U.S. same-store sales improving after nine straight quarters of declines, investors are betting consumers will continue seeking deals at Wal-Mart and have driven the shares up 24 percent this year.

As a result, late last month Wal-Mart briefly became the world's third most valuable company before slipping back into fourth place behind PetroChina Co. Wal-Mart fell 0.4 percent to $74.28 yesterday at the close in New York.

Now some investors are asking how much higher the shares can go. When consumers become more confident and middle-market retailers regain traction, investors may start looking elsewhere, according to David Abella, a portfolio manager with Rochdale Investment Management.

"In some sense, it is like gold," Abella said in a telephone interview. "It's a safe bet in an economy like this. If you start to see other retailers do well or consumers appear more confident, then it is time to take gains and get out."

The economy is recovering more slowly than some investors expected and some fear a renewed downturn, said Abella, who is based in New York. While that is not the likely outcome, when investors get nervous, Wal-Mart shares go up, he said.

The Rochdale Dividend & Income Portfolio fund owns 57,000 Wal-Mart shares, making the holding the fund's fourth largest. Abella said he plans to hold the shares because Wal-Mart's performance has been fundamentally sound and he expects the economy to remain sluggish this year. If the stock rises, he may sell, he said.

Market Capitalization

Wal-Mart's market capitalization raced past China Mobile Ltd. in May, then passed International Business Machines Corp. in June and then slid ahead of Microsoft Corp. and PetroChina to third before falling back to fourth behind Apple Inc. and Exxon Mobil Corp. With a value of $251.3 billion, Wal-Mart is worth the most since March 2004.

All of that happened after Wal-Mart said it would cooperate with investigations by the U.S. Securities and Exchange Commission and Department of Justice into allegations that the retailer systematically bribed Mexican officials to open stores more quickly.