Last week, Breaker reported an indicated resource of 18.4 million tonnes at 1.4 grams per tonne for 800,000 ounces, including a higher-grade core of 9.4Mt at 2.2gpt for 670,000oz.
The stock lost 17%.
Sanders told the Precious Metals Summit in Beaver Creek, Colorado, that the estimate was conservative.
"It's an open pit resource designed for an open pit prefeasibility study," he said.
Breaker is no stranger to heavy sell-offs, with the company's share price "slaughtered" when it released its maiden resource in April last year.
"The expectation was we were going to have more ounces," Sanders said.
Sanders said the maiden resource demonstrated mineability.
"The market didn't get it," he said.
"The market cares more about inferred resources you can't necessarily mine - we have the reverse view.
"Inferred resources aren't worth a cracker unless you can convert them into mineable resources."
Sanders says Breaker has already demonstrated mineability, with a high gold endowment of 5000oz per vertical metre and good continuity.
"From a technical point of view, this is 95% de-risked in my view, and the share price still hasn't taken off," he said.
Breaker will put out its PFS next month, which will include a maiden reserve.
Sanders believes the project's grade will go up 20%.
"For the starter pit, potentially I think the grade will go up 30%," he said.
"It will last about two years and translate to rapid payback."
Lake Roe's Bombora pit is expected to be 2.5km long and 250m deep.
Sanders believes Lake Roe will be a high-margin project.
"You make as much money mining a large open pit as you do going underground," he said.
Still, the belief is that the project will continue to grow.
"It's open in all directions after 225,000m of drilling," Sanders said.
"We've been putting out some of the best drill hits in Western Australia for the past two years.
"This is big and it's just the start."
Breaker shares traded as high as 47c in February, but closed at a 52-week low of 29c yesterday, valuing the company at $59 million.
