no it is called 'a market'. Obviously when asset prices go up people are tempted to sell. With the share price at 16c a buyer who got in at 14c may not be tempted to sell. At 21c that buyer is now sitting on an asset that has given him 50% profit - so the temptation to lock that profit in increases.
As I say on here daily - there are no sneaky little Montgomery Burns type people hiding under rocks manipulating the stock - it is an open market and if we did not always have buyers AND sellers, then we would not have a stock market
ISX Price at posting:
21.0¢ Sentiment: Buy Disclosure: Held