Will Birkenstock take the world by surprise? Framed by private equity firm L Catterton - itself controlled by LVMH - and backed by JPMorgan-Morgan Stanley-Goldman Sachs, the brand took advantage of its current good fortune to go public.

Comparison is not reason, but we know how often this type of configuration produces disappointing results. The examples of Crocs and Doc Martens, both discussed in our columns recently, spring to mind. In both cases, their IPOs crowned their commercial success before the hype suddenly deflated.

That said, both Crocs and Doc Martens now represent potential investment opportunities. Although their growth has slowed, both remain comfortably profitable, while their stock market valuations have fallen to very low multiples.

The Birkenstock case is different, at least at this stage. Sales have risen by 55% in two years, and by 22% in fiscal 2023. This continues the trend of the last ten years, when sales grew by an average of 20% per year.

Most of the brand's models command triple-digit sales prices. Moreover, sales growth in 2023 will be driven more by price increases than by higher volumes. Some may see this as evidence that we're approaching a plateau, and that the timing may well have been right for an IPO.

Now we have to justify a valuation of over forty times earnings. Admittedly, this is amply deserved if the annual growth rate is maintained. But should it falter, or for some reason L Catterton decide to reduce his position, investors who enter at this level of valuation run a severe risk of capital loss.