The AFR shows the turnover on the ASX 29.10.02 was $1.9 billion. A sale of $2 million could not cause even a ripple.
One of the advantages of being a small private investor, or even a large private investor is that we can move in and out of the market at will, unlike the institutions, whose orders can affect the market.
There is a situation, though, where you need to be careful - if you have a large holding in a small company. Then, you could be the market and you could not easily just buy and sell without affecting the price.
However, while you are in the top 100 stocks, a private investor should have no appreciable effect on the market.