North America's number one egg producer is no stranger to such events. In 2015, an epidemic had caused a reduction in its poultry stocks and a spectacular surge in its results; a similar episode, albeit less dramatic, also occurred in 2022.

In both cases, the flock suffered losses of no more than 10%. We can therefore measure the extreme sensitivity of prices to even a minor adjustment in supply capacity; and we dare not imagine the amplitude that a more severe hecatomb would cause.

On the other hand, the aftermath of these epidemic episodes was unfavorable, as producers rushed to rebuild their herds and even increase capacity as a precautionary measure, causing prices to plummet in the space of a few months.

However, Cal-Maine is no stranger to such fluctuations. Its sales, it should be pointed out, can vary by almost double from one year to the next - this has happened twice in fifteen years - and its operating margins can go as far into the red as those of Microsoft.

An illustration of this paradigm: between 2014 and 2016, Cal-Maine's return on equity averaged 28%. Over the following three years, from 2017 to 2019, it averaged around 4%. Rain follows fair weather, and vice versa.

In the wake of the 2022 shock, shares in the Jackson, Mississippi-based group were targeted by short sellers. Not unprecedented, their bet was that the response of producers - who rushed to rebuild their flocks - would durably depress prices.

The new avian flu epidemic - clearly a resurgence of the H5N1 virus - caught these birds of ill omen off guard. It has also propelled Cal-Maine's share price upwards, doubling in the space of twelve months, an unprecedented feat.

Before the inevitable backlash? Fortunately, the Adams family - which controls the group - imposes prudent management: very comfortably capitalized, Cal-Maine has no financial leverage and this year should have a cash surplus in excess of one billion dollars.

If history is any guide, the family will take advantage of the opportunity to distribute a new special dividend. Unless it decides to consolidate its sector, as its configuration lends itself to this: Cal-Maine is the leader, with a 15% market share; taken together, the next four producers control 25%.

Until a few months ago, the Group was valued at its historic low of x1.3 equity. Reflecting extreme investor pessimism and the short-seller offensive, this level had not been reached since 2009 and the low point of the subprime crisis.

Cal-Maine's valuation is now close to its historical ceiling of x3 shareholders' equity. During the great speculative episode of 2015, it had climbed to x4 equity. By 2022, this breakthrough had stopped at x2.5.