In a reminder that stretched valuations make for poor timing signals, Piper Sandler strategist Michael Kantrowitz observed in a Monday note that the S&P 500 is overvalued to the tune of around 8% relative to the firm's fair-value price-to-earnings ratio model.

The stock market’s current overvaluation should not deter investors from holding onto their stocks, according to a recent note from Piper Sandler. What Happened: Despite the S&P 500’s 8% overvaluation,

Piper Sandler Companies' investments in its restructuring franchise, starting some years ago, are paying off as it carries its weight these quarters. Read more here.

"Stocks can remain at rich valuations as long as a 'fear' catalyst doesn't arise from" interest rates, employment, or inflation, an analyst said.

US stocks gained on Monday with the S&P 500 (^GSPC) and Dow Jones Industrial Average (^DJI) reaching fresh record highs. Josh Lipton examines the key themes for investors on Asking for a Trend. After Elon Musk's SpaceX successfully landed its Starship rocket,

Michael Kantrowitz, chief investment officer at Piper Sandler, joins CNBC to discuss outlooks on over-valued markets, how he's positioning, and more.