Thinkin' Big has stormed to the top of Victoria Derby betting with a dominant Caulfield Classic win but trainer Gai Waterhouse has not ruled out taking on champion Winx in the Cox Plate.

The colt raced away with Saturday's Group Three race for three-year-olds and holds entries for next Saturday's weight-for-age Cox Plate at Moonee Valley, as well as the Derby and the Melbourne Cup.

"We'll sleep on it tonight," Waterhouse said of Thinkin' Big's spring program.

"We've got a few days and we don't have to make up our mind immediately.

"We'd already discussed it and thought we'll just see how he comes out of today.

"There's a few options. He's in the Cox Plate. He's in the Derby. He's in the Melbourne Cup.

"We brought him down for the Derby but we're just going to let the dust settle.

"It's a great way of training them. It gives you time to breath."

Thinkin' Big won the Gloaming Stakes (1800m) in Sydney earlier this spring before finishing third as favourite on a rain-affected track in the Group One Spring Champion Stakes (2000m).

With Tim Clark aboard, Thinkin' Big crossed to the front and was full of running around the home turn.

His rivals could make no impression as Thinkin' Big scored by three lengths over Chapada with 2-1/4-lengths to Sikorsky third.

He moved from $7 to $3 for the Victoria Derby (2500m) in two weeks and Waterhouse said he would stay all day.

"He's such a talented colt," Waterhouse said.

"The other day (in the Spring Champion) he just got bogged down.

"I just knew if he could get the rails they wouldn't be able to catch him. I knew he was better than the opposition, but we didn't see that the other day."