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 Juniper Networks, (NYSE:JNPR) gained slightly this morning after FBR upgraded the networking gear maker from Underperform to Market Perform.

So what: Along with the upgrade, analyst Scott Thompson boosted his price target to $25 (from $16), representing about 4% worth of downside to yesterday's close. While Thompson isn't exactly bullish on Juniper's appreciation prospects, he thinks that recent interest from activist investor Elliott Management will likely limit the stock's risk going forward.

Now what: According to FBR, Juniper's risk/reward trade-off is much improved. "In our view, the entry of activist investor Elliott Management into the JNPR story has changed the debate," Thompson noted. "We continue to believe Juniper's 2014 top-line growth is likely to be below consensus estimates (FBR flat versus consensus of +6%), but believe that the resulting EPS impact could be offset by what is likely to be increasingly stronger demands for the company to be more focused on the routing market and return much of the company's $1.8 billion net cash to investors through buybacks and dividends." With the stock up about 40% over just the past three months and trading at a P/E of 35, however, watching from the sidelines still seems like the prudent thing to do.