The stock markets have rocketed higher since Trump’s election win on hopes for big corporate tax cuts. This extreme rally has left stocks exceedingly overvalued and overbought today. A major selloff is long overdue and likely imminent. When stocks inevitably roll over and mean revert lower to rebalance away euphoric sentiment, gold is the main beneficiary. Gold investment demand soars when stocks materially slide.

Two trading days before the November 2016 presidential election, I published an essay that explored how stock-market action leading into elections really sways their results. Its conclusion based on long market history was “The stock markets overwhelmingly and conclusively predict Donald Trump will win!”  That was a hardcore contrarian stance before Election Day, when such an upset seemed impossible to most.

Since Americans voted for our next president, the flagship S&P 500 broad-market stock index (SPX) has soared 28.6% higher in 14.0 months! That extraordinary rally was mostly driven by hopes for big tax cuts soon with Republicans newly controlling the US government. And they indeed delivered last month with a massive corporate tax cut. That sets up a classic buy-the-rumor-sell-the-news scenario for these record markets.

Ever since that election, Wall Street has argued that stocks are surging due to strong corporate-profits growth. But that’s not true according to hard valuation data. In late October 2016 just before Americans voted, the 500 companies of the SPX averaged trailing-twelve-month price-to-earnings ratios of 26.3x. Even before Trump won, stocks were already very expensive and nearing dangerous bubble territory.

For the past century and a quarter, average broad-market TTM P/E ratios have run 14x earnings. That’s fair value for stock markets, and twice that at 28x is formally bubble territory. Rather ironically during his campaign, Trump often warned about the stock-market bubble created by the Fed! While he loves these same stock markets now, they are a lot more expensive after this past year’s massive taxphoria-fueled rally.

2017 indeed proved a strong year for corporate profits as optimistic Americans spent money fast. Yet at the end of December a couple weeks ago, the elite SPX companies were averaging a TTM P/E way up at 30.7x! That’s well into bubble territory, and history has proven stock markets never fare well for long after valuations are bid up to such unsustainable extremes. That guarantees a major stock selloff looms.

Over roughly the same post-election span where the SPX blasted up 28.6%, SPX valuations rose 16.8%. That means about 6/10ths of the rally was driven by multiple expansion, higher valuations. Only 4/10ths can be attributable to rising corporate earnings, and even that is suspect. The economic optimism that was unleashed by the Republican sweep was huge, driving big spending. But that anomaly won’t last for long.

And the Republicans’ corporate tax cuts won’t magically rescue stocks. While good news for the US economy, they won’t do enough to work off today’s extreme bubble valuations. Wall Street estimates are generally for 10% corporate-profits growth this year due to lower taxes. That would merely push the SPX P/E back to 27.6x, near-bubble levels. Stocks are now way too expensive for corporate tax cuts to help much!

As the stock markets surged into the tax-reform bill’s actual passage in recent months, contrarian traders assumed any stock selling was being delayed.  Why realize big capital gains in 2017 if tax rates might be significantly lower in 2018? But the stock markets have blasted even higher so far in January, with no meaningful selling yet materializing. That has left the SPX extremely overbought technically, a bearish omen.

In the first 4 trading days of 2018, the SPX surged another 2.6% higher. That’s truly an extreme rate of ascent by any standard. There are about 250 trading days per year, so annualize out these early-year gains and the SPX is skyrocketing at a 163% yearly rate! Obviously, there’s zero chance 2018 could see such absurd gains. Ominously such a fast climb looks parabolic for a stock index as enormous as the SPX.

In late December the collective market capitalization of those 500 SPX companies was $24.4t.  Such a vast number gives the stock markets great inertia.  So a parabolic surge in the general stock markets will always be relatively muted. Unlike vastly-smaller assets like bitcoin, stock markets are far too large to catapult higher in the terminal phases of bull markets. The SPX’s early-2018 action has truly been extreme.