The U.S. cable operator controlled by the famous John Malone offers another convincing example. Just a few years ago, analysts would justify an investment in Charter by invoking the merits of the irresistible "Malone method": massive share buy-backs financed by low-cost debt.

But here's the thing: In the space of a few weeks, the cost of capital has tripled in the wake of rising key interest rates. In addition, the method is only viable if the underlying business continues to grow.

The opposite is feared here, as operating profit has stagnated for the past three years. While Charter still possesses a unique, non-replicable infrastructure, it is also suffering the full force of competition from fiber installed by mobile operators. Not to mention 5G, which, with all its announcements, should soon be arriving with an irresistible value proposition.

Charter's share price is exactly where it was six years ago. In the meantime, the group has spent $62 billion on share buybacks, half financed by additional debt. While operating profit has tripled over the period, interest expense is on course to follow a similar trajectory.

Financial leverage has been maintained at x4.5 EBITDA. Is this model sustainable when growth prospects are dwindling, the cost of capital is skyrocketing, and capital expenditure inflation remains severe? The question is worth asking, as witnessed by the recent fall in the share price.

Charter's free cash flow averaged $7 billion over the last three years. The current enterprise value - market capitalization plus net debt - still represents a multiple of x22 this profit. That's a high price to pay for playing with fire.