With economic worries sending luxury goods makers like Coach Inc. (NYSE: COH) and Tiffany & Co. (NYSE: TIF) well off their highs, at least one super-investor who isn't afraid to go against the conventional wisdom is taking notice.

Nelson Peltz and his Trian funds have upped their stake in Tiffany from 5.6% to 7.9% amid continued weakness in the company's share price -- the stock is already down 20% year to date.

According to the Wall Street Journal [subscription], Peltz has previously said he isn't seeking a seat on the company's board, but wouldn't rule out the possibility of taking an activist stance somewhere down the road. Another big drop could prod him to step in and try to make something happen.

Tiffany recently reported a weak holiday sales period, a strong indication that the economic malaise that started in subprime may be carrying over to more upscale consumers. In recent years, Tiffany's and other luxury goods makers have seen their markets expand to include more luxury aspirational customers. Dependence on less wealthy consumers for sales growth may be making the luxury goods sector less immune to economic woes than it has been historically.