40 years building exchanges..
> Only extremely wealthy people participate in stock markets, in general. Other people use one of those wealthy people as an intermediary.
This confuses a retail investor with a Clearing Member.
Anyone with a phone and a $10 brokerage account has direct, sub-millisecond execution access to US equity markets. Brokers are not wealthy patrons acting as gatekeepers, they are licensed utility providers providing the technical pipeline to the exchange, just like the power distributors who cable and sell you power. They are providing a managed service, being a direct link to the exchange. There are some platforms that are not DMA, direct market access, but there are numerous brokers who offer DMA. I personally don't trust non DMA access, but maybe for larger orders, it might be good to have a man in the middle as a service.
The graph on Google is a trade feed, the last traded price, not buys and sells. If you sign up to one of those discount brokers you have a feed of those buy and sell orders, the order book, live, not delayed like the google trades. No one gets the names of the people buying and selling until settlement. (How I know, I write that code that builds the order book and matches the orders for a living). Not even the brokers.
True large firms trade large orders amongst themselves so they can get a more stable price, but US regulators explicitly mandate real-time reporting for off-exchange and private trades. Once they trade a listed instrument they must report the trade within 10 minutes. Yes they do, this part is highly regulated, if they don't they will be penalised. It's also in their interest as the more pricing, the better the prices. (No conspiracies here, some people have broken the rules but the code is pretty easy to write to make sure this happens, I've worked on that too)