U.S. equities mostly finished lower on Thursday while the Dow inched up to a new all-time high above the 22,000 threshold. For the average investor, all the focus will be on the Dow's seventh consecutive gain, the quiet lack of volatility and the spirit of bullishness that currently pervades the market.

But below the surface good cheer, a number of signs should give investors pause. Most notably, perhaps, the Nasdaq is flashing another "Hindenburg Omen," when the number of stocks hitting new lows matches those reaching highs (imagine the majestic blimp ascending above the admiring crowd even as the flames start to lick its undercarriage).

This is the latest in a cluster of signals warning that the market's breadth -- the number of stocks that are rising versus companies that are falling -- is fading as buying interest narrows: The Dow Jones Industrial Average has suffered eight Omens over the past 30 days -- that hasn't happened since 2000, when the dot-com bubble was topping.

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Amid such warning signs, a lot of media attention is being lavished on major big-cap tech stocks like Apple (AAPL) and Tesla (TSLA). Meanwhile, deterioration of other blue chips, such as General Electric (GE) and IBM (IBM), are mostly ignored. That points to trouble.

The consistency of the Dow's gains itself are a point of worry indicative of overheated sentiment, and possibly a price bubble. Jason Goepfert at SentimenTrader notes that the Dow posted its eighth consecutive gain on Thursday. That's the fourth time over the past 200 days that the blue-chip index has climbed seven days or more to hit a new high.

Such a remarkable run of consistent rallies to new highs is unprecedented in market history. The last time we saw a similar pattern was at the end of July 1987 just months before the infamous October market crash. Before that, the September 1964 surge that gave way to a 20-year malaise in stocks.

Goepfert concedes that it's unclear whether current-day market trends will necessarily lead to trouble, since the rising popularity of ETFs and passive investing strategies could presage ongoing "streaky" trading. Less debatable, in his view, is the observation that "we're seeing a kind of comfort with rising prices that we haven't really seen before."

It's a tale of two markets right now, as the Dow soars while the Russell 2000 small-cap index moves below its 50-day moving average for the first time since late May. The Dow Jones Transportation Average is in even worse shape, testing its 200-day moving average and risking a breakdown from its nine-month consolidation range.

Something is "off" right now. Large-caps are massively overbought and relying on the gains of a handful of stocks (Boeing, Apple, and McDonalds, according to UBS. Divergences are multiplying. Breadth is narrowing. Sentiment and investor positioning is white hot. And yet the S&P 500 has barely budged over the last 11 sessions, with a range of just 0.3 percent representing the quietest trading conditions in the 90-year history of Bloomberg's index data.

Goepfert notes that the only other time the S&P 500 traded in such a narrow range -- while also hitting a new high -- was in November 1961. Stocks climbed for a couple more weeks before giving way to a 28 percent selloff in the six months that followed.

All of this is the set up heading into Friday's non-farm payroll report. Watch for a volatility breakout -- we're long overdue.

As usual in markets, there's no consensus on where we go from here. For instance, Capital Economics believes stocks can maintain their momentum until 2019, when the Federal Reserve's interest-rate hikes finally begin to bite. Wells Fargo strategists believe there is still upside given that many investors have been reluctant to chase the market's surge.

My advice: Considering lightening equity exposure here. How much better can things get?