July is a big month for half-time results, and some of them distract attention from the post-Brexit panic that has affected so many. Here are three that should remain largely untouched by EU fallout…

Risky oil?

Shares in Tullow Oil (LSE: TLW), scheduled to release first-half figures on 27 July, have just about doubled since their low point on 20 January. But since the company’s trading update on 30 June, they’ve turned tail again and have lost 23% to 203p.

What’s given investors the willies is Tullow’s ballooning debt, which stood at $4.7bn at the end of June — up from $4bn at the end of 2015. Tullow still has undrawn borrowing capacity and free cash totalling around $1bn, but using up $700m in just six months suggests that might not last long, and the firm estimates 2016 capex at around $1bn. With Tullow saying it needs to get debt down, investors are clearly fearing the possibility of a dilutive new equity issue.

Total revenue for the half should come in at $0.5bn, lower than the $0.8bn of a year ago, with gross profit down from $0.3bn to $0.2bn. Should you buy Tullow shares now? I can see a volatile year ahead with some sort of refinancing needed, but the long-term future should be healthy as long as oil prices rise further.

Mining comeback

The bottom for Anglo American (LSE: AAL) also came on 20 January, since when the diversified miner’s shares have more than trebled in value to 718p. Recovering iron ore prices have been largely responsible for the change in fortunes as China’s slowdown is starting to look less bad than feared. However, that country plans to reduce its steel capacity in the coming years, and that’s knocked iron ore prices back down a little.

Does that mean the share price surge is overdone? With a 38% fall in earnings per share currently forecast, valuing Anglo American shares at nearly 25 times earnings, I fear it might be — especially as there’s no dividend expected this year. There’s a recovery in earnings pencilled-in for 2017, and a very modest 0.6% dividend, but with the gyrations in commodities prices we’re seeing I’m really not convinced it’s time to buy.

Results for the first half should be with us on 28 July, so there might be a brighter outlook in there, but I don’t expect to see anything that would change my stance right now.

Pharma bouncing back

Also on 28 July, we’ll have half-year results from pharmaceuticals giant AstraZeneca (LSE: AZN). The EU referendum result gave AstraZeneca shares a boost and the flight to safety has sent the price up 14% since the day to 4,523p. Other than that, the shares have had a pretty flat couple of years, as the world has waited for boss Pascal Soriot’s restructuring and pipeline focus to bear fruit. The company had been suffering from the loss of some key patent protections and increased competition from generic drugs.

EPS is expected to slip by around 14% this year, and analysts currently have a further 1% drop suggested for 2017. Any brighter outlook than that suggested on 28 July could have a positive effect on the shares, as I can’t help feeling many folks are awaiting the first evidence of a return to profit growth.

Meanwhile, with the shares on a P/E of approximately 16.5 and a 4.4% dividend yields on the cards, AstraZeneca looks like a safe long-term investment to me.

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