What a dreadful January it’s been! With oil plunging below $30 a barrel at one point, and economic news from China getting worse, the FTSE 100 dipped as low as 5,640 points on 20 January — a massive 9.6% down on its end-of-2015 closing price!

Still, things are recovering cautiously, and with about half a day of January still to go the top index is back up to 5,980 points. And when markets are depressed, that means bargains, right?

Pharma recovery

Look at AstraZeneca (LSE: AZN), whose shares have lost 9% over the past 12 months, to 4,382p. How does the price of oil and Chinese economic woes affect AstraZeneca’s long-term pharmaceuticals business? Not at all!

AstraZeneca has been in the process of focusing on its core businesses and beefing up its drugs development pipeline ever since new boss Pascal Soriot took the helm in October 2012, and we’re not expecting a return to earnings growth until 2017 at the earliest. On 4 February, we should have full-year results, providing the latest news on the firm’s rejuvenation strategy.

Things looked very stable at third-quarter time, and we’ve also seen quite a number of promising milestones in drug development along the way — Q3 R&D costs were up 18%, “reflecting the recent start of key Oncology trials“.

Meanwhile, AstraZeneca is still nicely profitable, on a P/E of 15.5 and offering a likely 4.2% dividend yield.

Takeover boost

We should have full-year results from BG Group (LSE: BG) on 5 February, but they’ll take a back seat to the ongoing takeover from Royal Dutch Shell. Originally revealed back in April 2015 before the oil price slide had really set in, the plan was put to the vote this week and both sets of shareholders have voiced their approval — Shell on Wednesday and BG on Thursday.

BG’s share price fell back from its initial boost as falling oil raised fears that Shell was overpaying and that the merger would be called off or the terms changed, but we’ve seen a 16% recovery to 1,040p, which is largely in line with the Shell offer.

Mergers and acquisitions were always a big possibility after the oil price set asset values tumbling, and in this case I think BG shareholders are enjoying the better deal.

Engineering boost

Rolls-Royce Holdings (LSE: RR) has been through tough times, with its shares losing half their value since last April’s peak, to 540p. The cause was a series of profit warnings due to very tough trading conditions, and the company is firmly in turnaround mode right now.

Full-year results are due on 12 February, after a third-quarter update warned that “Further market headwinds increase uncertainty for 2016“. At the time, outlook for the full year was adjusted to the lower end of previous guidance, though I think that might still turn out to be optimistic.

If results are better than expected, we could see an uptick in the share price, but with EPS already forecast to drop by 43% in 2016 to put the shares on a forward P/E of 18, I wouldn’t be buying now.

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Alan Oscroft has no position in any shares mentioned. The Motley Fool UK has recommended AstraZeneca and Royal Dutch Shell. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.