Wunderlich Securities analyst Jason Wangler Tuesday reiterated a "buy" rating on Northern Oil and Gas (NYSE: NOG) and raised the price target from $17 to $20 per share.

In the report, Wangler noted, "Northern Oil & Gas has been on a nice run the last two to three months as the weather in the Williston [Basin] has improved and the activity in the region has increased accordingly.

"This growth should trickle down to growth for Northern,'' Wangler wrote.

The Wunderlich analyst also looked at some recent company mergers in the energy space to settle on a proper valuation for NOG, confirming his belief that the company is undervalued.

Medtronic discloses growth assumptions

Medtronic last week filed initial statements, called an S-4, with the Securities and Exchange Commission regarding its proposed merger with Covidien.

J.P. Morgan analyst Christopher Pasquale dug into the document and offered some key takeaways in a research note.

Pasquale noted that Medtronic's projections for revenue growth over the next several years were higher than his estimates but that their earnings expectations were more in line with his.

Medtronic expects revenue to grow at a 6.5 percent compound annual growth rate from fiscal 2014 to fiscal 2019, well above Pasquale's estimate of 3.6 percent through fiscal 2018.

"The S-4 doesn't contain details on the assumptions behind the projections, so it's unclear what is driving the upside in management's forecasts vs. our own and the Street's," Pasquale wrote.

Pasquale is maintaining his "buy" rating on Medtronic.

Neal St. Anthony,

Patrick Kennedy