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 Loews Corporation (L 2.44%) slipped 1% on Monday after Deutsche Bank downgraded the property and casualty insurer from buy to hold.

So what: Along with the downgrade, analyst Joshua Shanker lowered his price target to $51 (from $53), representing about 15% worth of upside to Friday's close. So while contrarians might be attracted to the stock's weakness in recent months, Shanker's call could reflect strengthening bearishness on Wall Street over Loews' turnaround prospects.

Now what: According to Deutsche, Loews' risk/reward trade-off is pretty balanced at this point. "L stock has been remarkably resilient in the face of constituent shares of [Diamond Offshore Drilling] and [Boardwalk Pipeline Partners] being down 24% and 54%, respectively, over the past six months," said Shanker. "Appreciation in [CNA Financial (CNA 2.54%)] stock has helped provide ballast, but the stability in Loews's stock essentially implies significant value appreciation in Loews Hotels, HighMount, BWP GP and unallocated investments. The appreciation of the non-public assets means that the hidden value in Loews has been essentially uncovered, leading us to revise our rating to Hold." With the stock now off more than 10% from its 52-week highs and trading at a forward P/E of 10, however, Loews certainly seems like a reasonable long-term value.