And so yet more proof lands in the in-box that people are still buying luxury – and this time I’m not talking about the products. I’m talking about stocks.

Hot on the heels of the revelation that Qatar’s sovereign wealth fund has bought a 5% stake in jeweler Tiffany comes the news that luggage maker Tumi’s value was up by over 50% after their IPO yesterday raised $338m.

Tumi is an interesting case. While Tiffany is a high-gloss luxury name with an element of cultural currency that gives an enduring boost to its brand equity (thanks in large part to Truman Capote and Audrey Hepburn), and is widely regarded as having Burberry-like potential across the globe, Tumi’s allure is slightly less obvious.

It in itself is not a particularly luxurious product – it’s known primarily for its black indestructible bags, though it is currently engaged in a push to make its products more fashionable – but it has a deep and powerful relationship with the luxury industry, because so many of those involved in the latter own cases made by the former. And though you could say the element of luxury attached to their brand is the luxury of not having to replace your suitcase because it will last forever, I think it has more to do with luxury-by-association.

Every fashion season, for example, when I get off the plane in Milan and Paris, I would say easily over 50% of the bags on the luggage carousel are Tumi. The fashion/celebrity flock totes them for travel with the same dependability they hang the latest It bag over their shoulders or on their arms, and the brand has unquestionably – and quantifiably – benefited from the halo effect.