Wall Street is in the midst of another frightening October.
Big tech stocks are plunging as earnings growth has slowed, interest rates have risen and the threat of a longer China trade war has intensified. These worries have hit other blue chips and smaller American companies too. There aren't many places to hide.
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As if all that didn't sound scary enough for investors, here's another possibly worrisome sign.
The current market correction is taking place just one month after the S&P 500 was trading at a record high. And the same thing happened earlier this year. The market reached a new high in January, only to crater in February due to fears about inflation.
Why is that a problem?
RBC Capital Markets head of US equity strategy Lori Calvasina noted in a report that this pattern of two record highs in a span of just a few months -- so-called "Twin Peaks" -- also happened in late 1999 and early 2000 before the dotcom bust and in 2007 before the Great Recession.
Cue the "Twin Peaks" jokes about cherry pie, Laura Palmer, cups of joe and whatever the heck happened in that recent Showtime revival if you want. But like the giant said to Agent Cooper in the original 1990 version of the show, "It is happening again."
This doesn't necessarily mean stocks will plunge in 2019. But valuations appear stretched. Yellow lights are starting to flash. History shouldn't be ignored.