Per the website gurufocus.com, which is updated daily, the U.S. stock market is significantly overvalued and, as of 8/19/17, the ratio stood at 130.8. This site also uses the ratio to forecast estimated total returns. It predicts that investments made today will, even including dividends, over the next few years provide the average investor with a lot more losses than gains.

Based on Buffett's preferred way of assessing these things, this is probably not a good time to be doing new investing. Indeed, investors might be better off gradually selling existing holdings to raise cash, against the possibility of buying more shares once the market takes a big hit, as overall it tends to do around every 4 years or so.

There is also the choice to acquire shares of only high value to price stocks. This can be done no matter how overbought stocks in general become. In my view, during a high-priced market like today's there are few good low price to book value candidates to be found. Nonetheless, there are still some securities with reasonable or even bargain prices in relation to other measures of value, such as free cash flow, price to sales, price to earnings, dividend yield for the price, and price to long-term growth potential. At least a handful of excellent candidates might be found among stocks sharing one or more of these measures.

At the table above are a few that look enticing now. If the market falls a lot from here, to me they would also be fine assets in which to invest more later on. Having a set of such value stocks can be a first step in an investor's research. How he or she winnows the field down to just the few most desirable ones is an individual thing and part of the fun. Meanwhile, considering the currently lofty level of the Buffett value ratio, it might be wise to keep a large amount of one's funds in reserve.