Whenever a downtrodden share starts to spike up again, we need to sit up and take notice, don’t we?

Doing the right things

That’s certainly what I thought when I noticed that mining and commodities giant Glencore (LSE: GLEN) shares have stormed up 125% since 20 January, to 154p. Given that full year results released on 1 March reported a 69% fall in earnings per share before adjustments, that might seem like a pretty contrary reaction — especially as cost savings and reduction of capital expenditure are the order of the day.

The share price strengthening seems to be mainly on the back of modest recoveries in commodities prices, with both iron ore and copper up around 15% since their recent low points, and oil heading ever closer to $40 a barrel, from under $30 in mid-January. The trouble is, the slump in demand from China doesn’t seem to be anywhere near its end, and we still don’t know how hard the country’s growth slowdown is going to be.

While Glencore’s debt is rapidly moving in the right direction and the company seems to be doing things right just now, I think we’re unlikely to have seen the end of volatile commodities prices just yet and Glencore is still a risky choice in the medium term.

Resurgent supermarket

Even before its just-announced tie-up with Amazon, shares in Wm Morrison (LSE: MRW) had been climbing nicely, and they’re now up 50% since 11 December, to 209p. Some of that will be due to a Christmas shopping period that really wasn’t too bad. And now that Morrison’s “ambient, fresh and frozen products” are to be sold to Amazon Prime Now and Amazon Pantry shoppers, at least some of the damage done by the supermarket chain’s painfully late entry into online shopping will presumably be ameliorated — and Tesco will surely be stinging at not being the one to get the plum job.

But I’m still a bit twitchy about supermarket shares on a forward P/E of over 19, especially as price competition is sure to get harder as Aldi and Lidl keep rolling out stores almost as fast as you can work those horrid self-serve checkouts.

Recovering oil

The rising price of oil has helped Cairn Energy (LSE: CNE) shares to a 37% rise since 20 January, to 173p — although to put that into perspective, the price is still down 60% in five years. Cairn isn’t profitable yet, but unlike some smaller strugglers it doesn’t have a debt millstone around its neck. In fact, as of 31 December 2015, Cairn had net cash on its books of $603m, saying it is “fully funded … to deliver its exploration and appraisal programme, as well as to take its North Sea developments through to free cashflow generation in 2017“.

And it also has the means to buy up assets when they’re cheap, having revealed on 22 February that it has acquired another 4.5% of the North Sea Kraken field to take its stake to 29.5%. I’m usually very wary of not-yet-profitable oil explorers, but Cairn looks like a promising prospect to me.

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