The most recent all-time high in the U.S. stock market isn’t too distant in the rearview mirror, but some investors are starting to worry that it could end up marking a top.

Equities have stumbled in October, with major indexes under pressure as an abrupt rise in bond yields has emerged as the latest negative issue for Wall Street, joining uncertainty over trade policy, concerns over global growth, and changing monetary policy from central banks across the globe.

While stocks have been able to push past those issues throughout 2018, hitting records as recently as last month, there is a growing concern that the cumulative effect of all these headwinds could be too much for equities to look past, making it difficult for them to resume their long-term uptrend.

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The yield on the U.S. 10-year Treasury note TMUBMUSD10Y, 0.669% briefly pushed above 3.25 early Tuesday, its highest level since April 2011, and up from 2.93% a month ago. The sudden and sharp increase could signal a new phase in a market that has enjoyed a protracted period of ultralow yields.

Higher yields equate to steeper borrowing costs for corporations and investors alike, and have caused a reassessment of equity valuations, already deemed lofty by some measures. On top of that, richer rates of so-called risk-free bonds can compete against equities, which are perceived as comparatively riskier. Climbing rates, however, have come against a solid backdrop for the domestic economy, with a number of economic indicators supporting the notion that the U.S. expansion continues apace.

“Even if the move in rates is a growth and not inflation story, at some level equity prices are likely to come under increasing pressure, as bonds become relatively more attractive, and air comes out of equity valuations,” wrote David Joy, chief market strategist at Ameriprise Financial.

Joy made the comments in a report entitled, “Have We Reached A Tipping Point?” According to Michael Wilson, chief U.S. equity strategist at Morgan Stanley, that question can be answered with a “yes.”

Wilson has been calling for a stock-market selloff for months, which he said would take the form of a “rolling bear market” that would impact different sectors and regions at different times. Because some key sectors — notably the technology and consumer-discretionary groups — have until recently held up, so have the broader indexes. The Dow Jones Industrial Average DJIA, +0.19% is up 7.2% so far this year, while the S&P 500 SPX, +0.29% is up 7.9% and the Nasdaq Composite Index COMP, +0.36% is up 12.1%.

That masks the recent weakness, however. In October, the tech, discretionary, and communications sectors — which house the market-leading FAANG stocks — have all struggled, sending the Nasdaq down nearly 4% this month. Currently, the Dow and the S&P are 1.7% below their intraday highs, while the Nasdaq is 4.2% below its own.

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“The break higher in interest rates last week appears to be the tipping point, enabling the rolling bear market to complete its unfinished business in these last bastions of safety,” Wilson wrote. “We’ve often found that it’s not the magnitude of the rate move that matters most for financial markets, but its speed. Last week’s surge checks both boxes—it was big and fast!”

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Market tops tend to be preceded by pronounced gains and then followed by sharp losses. According to data from J.P. Morgan Asset Management, the S&P 500 tends to rise 41% in the two years leading up to a top, on a total-return basis. In the three months before the peak, it gains 8%.

The S&P’s performance hasn’t been too far from that historical average. In the two-year period preceding the most recent record, it gained about 35%. In the three months going into the peak, it was up about 5%.

If the late-September records did represent a top for the market, history suggests investors haven’t undergone anything close to the decline they could expect. In the three months after a peak, the benchmark index typically loses about 7% of its value, per J.P. Morgan’s data. A year after the top, that decline widens to 14%, although those losses are subsequent recovered to a large extend. Two years after a top, the market is just 1% under the prior peak, as seen in the following table.

Courtesy J.P. Morgan Asset Management

According to Lisa Shalett, head of investment and portfolio strategist at Morgan Stanley Wealth Management, “markets trade according to expectations and in anticipation of turning points, often topping out well in advance of a peak in economic activity.” Current conditions “are among the best they have been this cycle,” she added, but “too much of a good thing is often bad, as frothy activity levels counterintuitively pull forward a downturn and set up a more severe correction.”

Shalett added that “even small disappointments on the economy or corporate earnings could lead to a correction” in the stock market, and that while the median stock “is not excessively valued, “with real rates and inflation expectations moving higher, multiples are likely to contract.”