InterDigital Inc (IDCC)

[F6]

wilco 24 -- shorts are not a unitary force, but instead are respectively as diverse as are the longs; they do not all act in unison or at the same time or with the same objective -- as the share price rises, some who are already short may cover, but others may add to their short positions and other shorts may initiate new short positions -- just as when the price falls, some longs sell, while others add to their long positions or initiate new long positions -- in general, it makes sense that as a stock rises to new highs, the short interest in that stock will tend to increase

re "squeeze" -- if the share price of a stock with a significant pre-existing short interest rises rapidly, those "old" shorts get deeper and deeper in the hole, and come under increasing pressure, including potential margin calls, to cover their short positions -- this can add additional buying pressure, thus amplifying the upward pressure on the already-rising share price