Silver prices may retreat as much as 20 percent this year as soaring demand for physical metal signals a “crowded” trade, said Barry James, the chief executive officer of James Investment Research Inc.

Sales of 1-ounce American Eagle silver coins have totaled 4,588,000 in January, heading for a record, according to data from the U.S. Mint. Silver futures in New York rallied 84 percent last year, climbing to a 30-year high of $31.275 an ounce on Jan. 3, as investors sought a haven against financial turmoil.

“The coin sales are an indication of the level of interest in silver,” said James, who oversees $2.4 billion in Xenia, Ohio. “It’s too popular. When the crowd discovers a good deal, it’s usually long over.”

Prices have more than doubled in two years as investors bought precious metals to protect against a weakening U.S dollar and Europe’s financial crisis. Holdings in exchange-traded products backed by silver have dropped 1.6 percent since touching a record in mid-December. The metal tumbled 24 percent in 2008 after gaining for seven straight years.

“After a period of outperformance from silver, we would be taking a little off the table,” James said. “It’s more likely that silver will have a correction in price rather than a surge.”