However, where the Dow differs from the Nasdaq is that, from the highs of 1999 to the highs of 2016, a buy-and-hold trader would have netted profits of 58 percent.
Lastly, Grasso took a look at the S&P 500 and noted that not long after the highs of 1999, the index experienced a rapid 50 percent drop. But when tracing a line from the two highs of the last 17 years, a buy-and-hold trader would have enjoyed gains of 40 percent.
"Here's the problem," concluded Grasso. "You can hold and, longer term, I think you'll be OK. But, what you need to know is that the support [in all three indexes] is probably 30 to 40 percent lower than where it is now," since that's how far the indices have shown they can fall after hitting records."
"Buyer beware," he said. "If you're OK taking a losses for longer-term gains, so be it."