The relationship between Americans' wages and the stock market's total value could be signaling a peak, TrimTabs Investment Research Chairman Charles Biderman told CNBC on Thursday.
But in the near-term, he's still bullish—saying the market is "rigged because of zero interest rates."
Rates aside, Biderman said wages and salaries were $7 trillion at the end of 2012. "It's $7.5 trillion now. The market cap at the end of 2012 was $17 trillion and now it's $26.5 [trillion]."
"If you look at the relationship between wages and salaries and the market cap, it's like 3.5 times," he continued in a "Squawk Box" interview. "The last two times it was close to this was in March of 2000 and October 2007."
Those just so happen to be the last two market tops.
While no one can say if history is set to repeat itself, Biderman said he's still bullish on stocks, but not because of an improving economy, which is cited as a reason by many other market bulls.
"Zero interest rate policy means if you have cash on the balance sheet you're not going to earn anything. So companies are taking some of that cash and reducing the amount of shares outstanding," he added. "If you track the number of shares, you track the amount of cash—supply and demand right now—shares are shrinking."
If buybacks slow or interest rates rise, Biderman said, the stock market's bull run could be derailed.
His cautious comments come as the bears are starting to roar a little louder from some corners of Wall Street, with two market watchers warning Wednesday of possible declines of up to 60 percent on eventual fallout from the Fed's easy money policies.