John Bradley must be the only actor so far to have found a screen role more violent and unlikeable than his one in Game of Thrones.

In GoT he’s the hero of his own comic subplot, and his hands are relatively clean; as Vernon Stynes in Traders he’s cowardly, obsequious, indignant, squirmy, conniving and murderous. It’s a relief to see Bradley play a bastard – we were beginning to think he didn’t have it in him – and it’s a performance that marks him as a creditable character actor with a lifetime of such roles ahead of him. We look forward to watching his sweaty weasely scumbags for years to come.

Vernon is a commodities trader in post-crash Dublin, where the Celtic Tiger is in the process of being flayed and turned into a rug. Former financial hotshots are either handing back their company BMWs or driving them into trees; the latter is known as committing ‘econicide’, and Vernon sees an opportunity. Well, he would, wouldn’t he? And like any 21^st Century chancer he sets up a website.

‘Traders’ is an online game in which two wretched souls liquidise and pool their remaining possessions, then fight to the death in an attempt to double their cash. The headiness of trading irresponsibly finds a nice schlocky metaphor – as far as high-concept ideas go, it’s a promising one. And when it remembers that it’s a satire, Traders pays dividends.

Foolish greedy Vernon has the temerity to call his murderous game ‘white-collar crime’, then corrects himself and calls it ‘up-market crime’, rebranding even as he speaks. One participating ‘trader’ offers to throw his expensive watch into the winnings ‘as a bonus’; another trader, female, makes a good threatening joke about the wage-gap: ‘You know the thing I find difficult about trading as a woman? Dragging fat, dead men into graves.’ This woman, you can tell, is going to break the glass ceiling and stab someone to death with the shards.

The problem with Traders is that there simply isn’t enough barbed wire wrapped around its baseball bat. It recalls American Psycho and Fight Club, but it doesn’t have the wildness of the former or the sly homoerotic subtext of the latter (a shame, for a film about men meeting online and patting each other down in bathrooms). It’s also hobbled by a bland leading man (Bradley is only supporting). Killian Scott’s Harry is our reluctant anti-hero, but the thing from Fight Club he most resembles isn’t Edward Norton but the Ikea furniture.

Traders still has some pleasurably deadpan moments. ‘If you ever find yourself in a fight to the death,’ says Harry in voiceover, ‘go for the throat. The throat is full of blood and air, and humans don’t last long without blood or air.’ But if you want a film that makes serial murder both funny and moving, watch Ben Wheatley’s Sightseers.

Not heavy enough for drama or sharp enough for satire, Traders is a blunt, simple weapon that just about does the job.