McKesson Corporation (NYSE:MCK) shares crashed over 20% today after the health care company reported disappointing results for the fiscal second-quarter and issued lackluster guidance. MCK posted EPS of $2.94, below the Street’s $3.04, and lowered its F17 guidance range by $1.10 to $12.35-$12.85, which will now likely be down vs F16.

However, Standpoint top analyst Ronnie Moas views the pullback as an attractive buying opportunity, and upgrades the stock from Hold to Buy, with a price target of $156, which represents a potential upside of 25% from where the stock is currently trading.

Moas noted, “The stock has collapsed and is now trading at $119. I would reinstate this name at this time with a target of $143 for 2018 that would be 12 times $13 in EPS potential. I think the market is over-reacting here. MCK reduced EPS forecasts for 2017 by 7% and the stock is down 25% right now. It is very rare to get an opportunity at a mega-cap name trading 40% off its 52-week high and that is where MCK is right now.”

“I may be a little bit early trying to pick a bottom here as there will now be tax-loss selling weighing on this name and if a few of the major holders in this mega-cap stock try to exit that will also weigh on the shares,” the analyst added.

According to TipRanks.com, which measures analysts’ and bloggers’ success rate based on how their calls perform, 5-star analyst Ronnie Moas has a yearly average return of 5.1% and a 69% success rate. Moas has a 11.8% average return when recommending MCK, and is ranked #51 out of 4188 analysts.

Out of the 18 analysts polled by TipRanks, 12 rate McKesson Corporation stock a Hold, while 6 rate the stock a Buy. With a return potential of 43%, the stock’s consensus target price stands at $178.06.