Market Makers

Hi, I'm new to this forum. Can anyone explain to me what is going on with the BIG share price. I've noticed that up until today there were considerably more Buyers than Sellers which I thought would give support to the share price around 70c. Yesterday there were something like 5 buyers with limit prices at 70c for over 200,000 shares. Today around 11.18AM over 200,000 shares were presumably bought? as I noticed that the buyers at 70c had all gone. And now there are 312,522 shares listed under Buyers and 538,354 shares listed under Sellers (according to the CommSec website) which is a complete reversal of what was being shown yesterday in terms of percentages for Buyers and Sellers.
I would have thought that if people were buying the shares then the shares would go higher rather than lower in price?
Can anyone explain the roll of the Market Makers here? I'm not accusing anyone of anything here but was wondering if they can move the price lower and then sell shares to the Buyers who have put in limit Buy orders, and if so is this the reason why the shares have been marked lower with the current Bid price at 0.685, where as yesterday the Bid price was around 0.73