A way to manipulate bitcoin price bids/demand would be to release and popularize services around the world that has users do the number one big NO-NO for Bitcoin, has users trust another entity to hold custody of their bitcoin. Today, you see many examples of that where users are keeping their Bitcoin in exchanges which exposes them to hacks, or many services that do not allow users transfer ability of the Bitcoin; examples:
Traded Bitcoin Futures (cash settled and they dont give bitcoin delivery!)
Revolut
Square Cash App
Circle Invest App
Robinhood
Many other 'custody' examples in developing countries
hack.
Stay away and secure/safely backup your own Bitcoin in your own wallet.
A bigger supply can be used to flood market for short selling supply if there's any degree of certainty of an amount of bitcoin that wont be touched at these custodial entities. Ever wonder how Gold and other commodity prices are manipulated?

i've felt it was important to add the PSA and alert people:
DO NOT LEAVE YOUR BITCOIN ON COINBASE