Wall Street's post-election honeymoon with The Donald could well be ending — and with it, the historic three-month uptrend that pushed the Dow Jones Industrial Average from a pre-election swoon below 17,900 to within a point of 20,000.

Trump’s press conference on Wednesday didn’t help, but the market’s turn is about more than just that. Valuations are stretched. Investors are over their toes, so to speak, with an aggressive bullish position. And sentiment has rarely been higher. Any disappointment could unleash a torrent of pent up selling pressure and cast a pall on Trump's first weeks in office.

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On the surface, the situation seems tranquil. The Nasdaq has climbed for seven straight days through Wednesday, reaching a new high. But the S&P 500, the Dow and the Russell 2000 have been trapped in an extremely tight range for the past month. Earnings expectations for the Q4 season are high. Expectations for Trump's fiscal plans are extremely high.

On the other hand, equity market breadth continues to deteriorate and evidence of buying activity in safe haven assets — Treasury bonds and gold — is rising. Gold futures are challenging the $1,200-an-ounce level and crossed up and over their 50-day moving average for the first time since the first week of November. Treasury bonds are enjoying the first sustained uptrend since the summertime rally that peaked in July.

Monday marked only the third time in recent history that the Nasdaq Composite closed at a new high despite more issues declining than advancing. The other two times were July 1998 and February 2012. Both times, stocks declined almost immediately.

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In 1998, the index went on to lose a quarter of its value in the months that followed as Federal Reserve interest rate hikes destabilized foreign currency and bond markets. There are some similarities to what's happening now as the surge in the U.S. dollar and U.S. interest rates since the presidential election has unnerved markets from China to Mexico.

In 2012, the index recovered from a short-lived pullback to hit new highs before losing 12 percent over the next couple of months.

On Wednesday, the Nasdaq hit a new high despite the fact that only 45 stocks on the Nasdaq exchange recorded a 52-week high. That's fewer than 1.7 percent of all issues. And that's the worst-ever reading on a day the index reached a new multi-year high. Something is clearly amiss.

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^DJI data by YCharts

Smart money traders are increasingly getting cold feet. The "Smart Money Confidence" index maintained by SentimenTrader has dropped below 20 percent for the first time since last summer, one of the few times in the last 17 years confidence in this group has fallen this low. In the past, almost every prior instance resulted in stocks moving lower with "substantial downside," according to Jason Goepfert.