US  companies are sitting on record amounts of cash, and when they’ve put cash to work over the past few years they’ve tended to do so through buybacks and dividends — not capital expenditures. But Charles Schwab’s Liz Ann Sonders says the tide may be turning.

In commentary on Schwab’s website, Sonders says the gap between profits and investment has been the result of “the attention by companies on productivity, efficiency, and profit margins”. But she says that while productivity growth spiked after the Great Recession, it has since slowed markedly. ” If productivity weakens from here it may be a short-term warning signal for the stock market, but it suggests the need for capital investment to help increase productivity,” she says. “The long period of under-investment appears to have taken a toll on corporate efficiency. The five-year annualized growth rate of investment has dropped to the lowest level in the post-WWII period. Companies are sitting on nearly $2 trillion in cash and they also face upward pressure on the minimum wage. That should be motivation to boost capex to boost productivity.”

Sonders also provides a good deal of data on the aging state of US capital stock. “The average age of the capital stock is now at historical peaks, even for quickly-depreciating sectors like software and information processing equipment,” she notes. “Tech investment has dropped to a near-15-year low as a share of overall investment.”

Other reasons to expect a capex increase: rising CEO confidence and increased commercial lending activity, which Sonders goes into more detail on. She expects a capex rebound will in particular help technology and industrial firms.