Today I’m looking at the investment case for three London fallers.

Falling into a hole

An unexpected recovery in commodity prices has seen stocks like BHP Billiton (LSE: BLT) shoot higher in recent weeks.

But this progress has hit the skids more recently as prices of bellwether materials like copper and oil have moderated — indeed, BHP Billiton saw its share value fall 6% between last Monday and Friday.

And I believe the mining sector could be in line for further pain as demand data continues to disappoint. Chinese industrial production rose just 5.4% in January and February, according to data released at the weekend. This was the worst result since 2008, and follows horrendous trade numbers last week that showed China’s exports fell to a seven-year nadir in February.

BHP Billiton is expected to suffer an 87% earnings decline in the period to June 2016, resulting in a mega-high P/E multiple of 80.2 times. Against a backcloth of severe Chinese economic cooling and chunky commodity stockpiles, I believe the firm represents far too much risk at current prices.

Eateries looking oversold?

Catering specialist Restaurant Group (LSE: RTN) also took a battering last week after releasing a disappointing outlook for 2016 — the business conceded 26% between Monday and Friday.

Underlying revenues have fallen 1.5% so far in 2016, the company advised, “reflecting a softening in consumer demand and weaker overall consumer confidence” since the dying embers of 2015. And Restaurant Group advised that “this more challenging environment and recent trading patterns are likely to persist.”

Still, the City expects the Frankie and Benny’s owner to enjoy a 4% earnings rise in 2016, resulting in a P/E rating of just 11.5 times. And a predicted 18.1p per share dividend yields a delicious 4.5%.

While Restaurant Group could be subject to near-term downgrades should market difficulties endure, I reckon now could represent a tasty entry point for brave investors as new store openings continue rolling, and Restaurant Group’s huge brand investment attracts customers back through the doors.

Crude troubles

Like BHP Billiton, investor appetite for oil services provider Hunting (LSE: HTG) has dried up following recent heady gains, the company conceding 12% between last Monday and Friday.

Hunting advised earlier this month that revenues collapsed 42% year-on-year in 2015, to £810.5m, the result of lower global drilling activity and production spending across the oil industry.

And while the business introduced vast cost-cutting last year to mitigate these problems, the prospect of prolonged crude weakness threatens to heap further pressure on Hunting and its peers, in my opinion. Indeed, BP and Shell alone have announced even more capex cutbacks recently for 2016 and beyond.

Hunting is expected to endure extra bottom-line woes as a result — the company is expected to slip to losses of 0.95 US cents per share in 2016 from earnings of 310 cents last year. And I don’t expect a recovery any time soon as the oil market’s supply/demand imbalance worsens.

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