Those who bought stocks as they soared to new records last week amid rising optimism for a trade deal are probably suffering buyer’s remorse after President Donald Trump said the U.S. hasn’t agreed to a rollback of tariffs on China. Are those regrets warranted?

As the Dow Jones Industrial Average, S&P 500 Index and Nasdaq Composite Index all set new marks last week, there were no shortage of studies released that crunched data going back to the 1920s to prove that purchasing stocks when indexes hit record highs generates better risk-adjusted returns than simple buy-and-hold strategies. As Meb Faber — the chief investment officer at Cambria Investment Management, who conducted one of the studies — pointed out, while buying at the highs isn’t really “a system anyone would want to implement,” the data is “an acknowledgement that all-time highs are nothing to be afraid of.”

The thing is, despite the recent surge in markets, it appears that plenty of investors are afraid. Rather than going all-in on stocks for fear of missing out, investors are showing almost unprecedented restraint. Money continues to pour into money-market funds, with assets standing at $3.51 trillion as of last Wednesday, up from $3.05 trillion at the start of the year, according to the Investment Company Institute. At the same time, they have pulled $267 billion from equity funds year to date.

Put another way, almost half a trillion dollars have been put into cash even as the MSCI USA Index of equities jumped 23.5% this year through Friday. The last time so much money went into cash was in 2008 as the financial crisis was heating up, and it’s a marked difference from 2013, the last time stocks were having a good as year as this one. Back then, money funds only attracted $28 billion.

Money funds aren’t the only sign of significant investor caution. Notably, State Street Global Markets’ monthly index — which is derived from actual trades and covers 15% of the world’s tradeable assets — shows that investors this year have been less confident in the outlook for equities than even during the financial crisis.

It’s good to see investors showing so much discipline, especially with valuations on the high side. The S&P 500 is trading at 17 times the following year’s projected earnings. That ratio has been higher only once since the economy began to recover from the financial crisis, and that was during late 2017, just before the S&P 500 took a nasty fall, declining 10% over the course of a few weeks in late January and early February 2018.

Perhaps the caution is a sign that investors know a trade detente only brings a new set of issues to the forefront. The first is whether equities can keep rising if an agreement only reinforces the notion that the Federal Reserve is done cutting interest rates and may even start talking about boosting them sooner rather than later. In the absence of earnings growth, a strong case can be made that the only reason stocks have managed to rally is because of the Fed’s dovish pivot earlier this year and three subsequent rate cuts. Based on fed funds futures, traders aren’t convinced the central bank will ease monetary policy further any time in the next two years.

The second is whether the economy can pick up enough to allow companies to meet lofty earnings estimates for next year. Although analysts have slashed their fourth-quarter earnings forecasts for members of the S&P 500 to an average decline of 0.3% from an increase of 7% in June, estimates for 2020 have barely budged, remaining stubbornly high at 9.7%.

So while history shows there’s no reason to avoid buying stocks at all-time highs, there are always exceptions.  This could be one of them.

This article provided by Bloomberg News.