Falling bond rates have been instrumental in driving the stock market higher in 2019, right? It’s a bit more complicated than that.

Sure, in the broadest sense, the tumble in 10-year yields has coincided with a sizable rally in the S&P 500, which is up 12%. But a closer look shows a more nuanced relationship in their day-to-day swings. Over the past five months, the S&P 500 has dropped a net 8% in sessions the bond rate has sunk, according to Credit Suisse.

By contrast, up-rate days have seen S&P 500 gains adding up to 30%.

The relationship shows it’s not quite right to say equity investors are unilaterally in love with lower rates. As the 10-year yield sinks toward 2.2%, Fed funds futures are now pricing in around half a percentage point of central-bank easing by the end of the first quarter of 2020. And the S&P 500 is mired in a 5% slump.

The pattern was on display Tuesday, with the S&P 500 failing to hold gains as 10-year Treasury yields slipped to the lowest level since September 2017. Futures fell again Wednesday, with the bond rate slumping toward 2.2%. While President Donald Trump has blamed Fed tightening for holding back equity gains, the fact is stocks haven’t taken lower rates in stride, either.

Why is it happening? Maybe it’s the doubt the Fed has much chance of jump-starting the economy. After all, the U.S. is still by some measures mired in the weakest recovery since World War II after years of stimulus. Or it’s the fear over deflation and concern lower rates are a sign of weakening growth, something that doesn’t go well with stocks.

Whatever the reason, Jonathan Golub, chief U.S. equity strategist at Credit Suisse, is not siding with Trump that lower rates are good for the equity market.

“Higher rates from here should support further upside for equities, while a potential Fed rate cut would be less positive for stock prices than many investors believe,” Golub wrote in a note to clients.