Sometimes the most interesting Wall Street news isn't what analysts are excited about, but what they're backing away from. Wednesday brought a pair of notable downgrades that caught the market's attention.

Let's start with the homebuilder. Raymond James analyst Buck Horne downgraded KB Home (KBH) from Outperform to Market Perform. That's Wall Street speak for "we used to think this stock would beat the market, but now we think it'll just kind of... exist." KB Home shares closed at $56.83 on Tuesday, and now investors are wondering what changed Horne's outlook on the housing market.

The other downgrade hit the satellite data space. Alliance Global Partners analyst Brian Kinstlinger downgraded Spire Global Inc. (SPIR) from Buy to Neutral and absolutely slashed the price target from $17 down to $9. That's nearly cutting your expectations in half, which is never a great sign. Spire Global shares closed at $8.62 on Tuesday, trading below even that reduced target.

These rating changes reflect how quickly analyst sentiment can shift when companies face headwinds or when the macro environment changes. For investors holding either stock, it's worth understanding what drove these analysts to pump the brakes on their previous enthusiasm.