While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of ON Semiconductor Corp. (NASDAQ:ONNN) slipped 1.5% today after MKM Partners downgraded the chip company from "buy" to "neutral."

So what: Along with the downgrade, analyst Ian Ing lowered his price target to $8 (from $10), representing about 13% worth of upside to Friday's close. While value investors might be attracted to ON's share-price slide in recent months, Ing believes that the company's appreciation prospects remain limited given its exposure to strong global economic headwinds.

Now what: While MKM acknowledges that ON is nicely positioned for a recovery, it isn't seeing that recovery just yet. "Our thesis is that highly diversified and manufacturing-heavy ONNN is heavily dependent on a global macroeconomic recovery to drive semiconductor demand," noted MKM. "We look to turn more constructive should macroeconomic improvement and/or rationalized semiconductor supply place ONNN on a sustainable trajectory of improved GM/OM leverage." Of course, with ON shares now off about 20% from their 52-week highs and trading at a forward P/E of 10, now might be one of the best times to bet on that improvement. 

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.