velocity vs. acceleration
For investors, earnings velocity is the rate of change of earnings.
Earnings acceleration is the rate of change of velocity.
If a company is growing earnings per share at a steady +10% annual rate, it has earnings velocity of +10% and acceleration of 0.
To have earnings acceleration, the rate of earnings growth has to increase. The growth rate pattern has to be something like: +10%, +12%, +15%…
Both velocity and acceleration can be negative as well as positive. If velocity is negative, earnings are shrinking. If acceleration is negative, the rate of earnings growth is slowing down. For growth investors, both are bad signs.
as applies to growth investing
Having any earnings per share growth is better than having none. Having eps growth that’s fast, and faster than that of the average stock, is an important characteristic of attractive growth stocks.
Having eps acceleration is also important. Its presence typically creates the largest price earnings multiple expansion.
Acceleration is a two-edged sword, however. Securities analysts looks for signs of earnings growth deceleration as an early warning sign that a company’s period of superior growth–and therefore of its attraction to investors–is coming to an end. So it’s often the case that the PE will begin to contract, even though absolute growth is high, because that growth is starting to decelerate.
why this can be important: performance implications
This can create an odd situation between the performance of two stocks, A and B.
Annual growth of A’s earnings: +20%, +35%, +45%, +25%.
Growth of B’s earnings: +10%, +12%, +15%, +18%.
In the first two years, Stock A most likely has outperformed Stock B. By year 4, B is most likely outperforming A, even though the rate of growth of A’s earnings is continually better than B’s. That’s because A’s earnings are beginning to decelerate, while B’s are not.