"But while prices of a lot of commodities have already risen and may have reached their peak - they may not fall nearly as much as one would think," he told Reuters.
Several commodities are at or near multi-year highs, with copper eyeing 16-year peaks, New York coffee at five-year highs, gold less than $30 away from a 16-1/2-year top scored in December and oil having struck a record last October.
The Reuters CRB index of 17 commodities futures rose last year to its highest since the end of the commodities boom of the early-1980s.
Christian said investors were realising that the basic capital appreciation of commodities might not match the levels of recent years.
"You find people saying 'OK, I made good amounts of money 2001-2004 on being long of commodities - now what do I do on both sides of the market?'"
"You could find people investing to take advantage of declines in prices," he said, adding that investors might take profits in a futures contract and buy options covering both sides - a so-called options strangle.
He also noted a trend for picking individual markets as opposed to commodities as a whole asset class.
"So you go from this rifle-shot approach of saying I want to buy commodities across the board to saying I'm interested in soybeans and corn but not cocoa, for instance."
Among metals, Christian said, silver showed the most promise, with prices seen gaining sharply due to tighter fundamentals than the much more liquid gold market.
"Silver could go to $9-$9.50 in a spike, before coming back $6.50 to $7.50," he said.
Silver is currently around $7.15 per ounce.
Chrstian said metals remained the most popular markets among funds.
"If you look at gold, it is one percent of the physical world commodity market and more than 50 percent of the world's derivatives commodity market," he said.
"The gold derivatives - futures, forwards, options - are more liquid than even the oil market."
Christian said gold prices either peaked at December's 16-1/2-year high of $456.75 or would probably do so in the first half of this year, but he did not expect a rapid fall after that.
"It might be the case that nominal gold prices could trade $370 to $440 next year, they could trade either side of $400 for quite a substantial period of time."