This was the case last autumn, when a violent air pocket sent the Minneapolis-based group's valuation to historic lows. On this subject, see 3M: Another mega-cap under pressure, published in these very columns in October.

On Friday, following the publication of half-yearly results, the said valuation experienced its most festive day since 1987, with a daily jump of 23%. It was a long way off, of course, as 3M's news continued to be tainted by painful legal developments linked to the cases of its failed hearing protectors and PFAS chemicals.

Fears of a Bayer-style nightmare scenario were rife. But rather than seeing the glass as half-empty, investors now see it as half-full, and fears of finding another skeleton in the closet have clearly faded.

At the same time, the appointment of Bill Brown - on the crest of a wave following the successful turnaround of L3Harris - as CEO on March 12 was clearly very much appreciated. The spin-off of Solventum - 3M's former healthcare division - was successfully completed the following month.

But beyond his many talents, and judging by the market's reception of the Group's half-year results, Bill Brown seems to have mastered the subtle art of financial communication, since the recent publication, while well turned out, offers nothing particularly exhilarating.

Sales are down slightly, and operating profit - adjusted for the exceptional provisions booked at the same time last year - is little changed. Nor has there been any improvement - or rather the opposite - in cash flow, although it would be premature to draw any conclusions on this subject over six months.

We were wrong in October when we assumed that the dividend would remain unchanged and share buy-backs would be suspended, but it is precisely the opposite that has happened over the last six months. The good news is that, for the first time in a long time, the share buybacks in question were carried out at a valuation that made sense.

Apart from its legal affairs, 3M's real challenge - at the heart of Bill Brown's mandate - will remain to return to organic growth. Despite substantial R&D budgets, which are set to increase further, organic growth has been lacking for far too long.