It can be one share to one million shares as well.
It is decided by selling pressure and buying pressure actually.
This can be visualized as tug -o - war.
Suppose SBIN is at 100. Now there is a seller who is continuously putting limit sell order at 100 itself. He started exactly at 9:15 AM and continued the process for whole day.
Now any buyer who came to market will get SBIN shares at 100 only.
Now suppose some other small person wanted to sell his SBIn shares asap. So he came in and fired sell order at market. Now some hopefull buyer who had fired limit order buy at 99 will get his fill and LTP will reduce to 99 for a moment. It may go down further as more and more market sell orders come in but never go above 100 unless and until That big buyer continues to sell at 100 and no equally matched poweful buyers come in who can digest all the quantites of ther seller and then move price to 101.
So to move price 1 rs up may be million buyers.
to move price down by 1 rs just single seller.
Now this is a continuous process and not rigid.