Last month, US employers added 134,000 jobs (pdf). While this was well below economists’ expectations of 185,00, there was plenty of other data to confirm that the US economy is on a roll—so much so, in fact, that traders appear to be wondering if there’s such a thing as too much good news.

September was the 96th consecutive month of job gains, the longest on record. The two previous months were revised to show 87,000 more jobs were added that previously reported. On average for the past three months, 190,000 jobs have been added each month; a healthy pace.

Meanwhile, the US unemployment rate fell to 3.7%, the lowest since 1969.

The jobs data pushed yields on 10-year Treasury bonds to 3.22%, the highest since 2011. Yields rise as bond prices fall, with investors ditching the US asset that serves as a haven.

Treasury yields were already surging higher. By the middle of the week, they had reached their highest level in seven years. On Wednesday, yields had their steepest daily jump since the turmoil that followed the election of Donald Trump.

It’s a sign that traders are expecting the Federal Reserve to keep raising US interest rates, even though the upper limit was just raised to 2.25%. Earlier this week, the central bank’s chairman Jerome Powell said the economy was looking “remarkably positive” (paywall) and that the US could be on the verge on an “historically rare” era of ultra-low unemployment and steady inflation. “There’s no reason to think this cycle can’t continue for quite some time, effectively indefinitely,” Powell said.

Traders had every reason to take Powell’s confidence to heart, as other data published this week showed that private-sector payrolls increased by the most in seven months in September, and that activity in the services sector accelerated to its highest on record.

But traders also seem to be anticipating a downside to all these rosy indicators. Stock markets fell around the world (paywall) yesterday on fears that the good US economic data would encourage central banks to raise interest rates too high, to the point that economic growth gets restrained. The S&P 500 fell 0.8%, its biggest one-day decline since late June. Higher US yields are also hurting emerging-market stocks as investors worry about how companies will pay off increasingly expensive dollar-denominated debt.

With the US economy growing at a strong clip, the Fed will keep raising rates and is even considering taking them past the neutral point—that is, the point where rates neither spur or slow economic growth. But for the rest of the world, higher US interest rates will be harder to manage, as their weaker economic momentum could be knocked off course. And so traders must figure out how to navigate this multi-speed world.