The prospect of oil prices falling below $40 receded earlier this year amid a crude rally, but with futures sliding again, investors shouldn't rule out a three-handle, Again Capital founding partner John Kilduff said Thursday.
"Christmas time we'll probably be rebounding off new lows off of the mid to low 30s," he told CNBC's "Squawk Box." "We have a lot to go. We're going to take out the March lows of $43 and trade down to the 30s in my view."
U.S. crude was trading around $49 Thursday morning. The benchmark touched a four-month low this week.
A growing global glut of diesel fuel could be the next catalyst, he said, noting that Saudi Arabia and China have ramped up their refining capacity and are now flooding the Asian market with diesel.
"You hear analysts come on all the time talking about this golden era for refiners," he said. "You're still making 30 bucks a barrel turning crude into gasoline here, and so there's been a rush into it, and now it's going to see the tipping point just the way crude hit a tipping point last year."
Recent developments in China and Iran may also contribute to another leg down in oil prices, Kilduff said.
"I've been hearing a lot about how this Chinese stock market crash doesn't affect anything and doesn't count almost. For me, it's going to affect consumer confidence there," he said.
"If we see things like ... automobile sales coming down, that hurts the outlook for oil demand growth and gasoline demand growth going forward."
Meanwhile, China is beginning to buy up Iranian oil currently being stored in floating tankers, Kilduff said.
Analysts believe Iran may have as much as 40 million barrels of oil sitting offshore. That crude could soon flood the market if world powers lift sanctions on the country following the deal over Iran's nuclear program.