The earnings of individual day traders are not usually made public. There is good reason for this, as day trading for oneself does not require any type of public disclosure of earnings. There is not any incentive for most profitable traders to publish their earnings, and if they do not want anyone else to know how they are making money they do not want to attract unneeded attention to themselves.
Usually when an individual trader makes their earnings public, they do so when they are selling a trading system, educational material, or school. Anyone considering paying for a trading education from someone who publishes their earnings should be weary about the veracity of the claims. If, for instance, the trader shows huge gains month after month and year after year without any drops in their account value, it is unlikely that they are being truthful. Every trader experiences losses at some point (unless they are merely getting paid as an intermediary for an institution).
Many successful traders have the occasional massive trade, when they may make hundreds of thousands or even millions of dollars. Unless you know them privately, you will probably never hear about it.
Big Bank Trading Revenues
Many people may be dazzled by the trading revenues at big banking institutions, and believe that this is attainable for them. While this is possible, the revenues generated from trading at large institutions is mostly from providing liquidity to the markets and matching client orders internally and externally (for a profit to the bank.) Banks have mostly been prevented from taking any sort of speculative trading positions from what is known as the Volker Rule. To see the SEC page on how the Volker rule restricts banks from proprietary trading as a part of the Dodd Frank Act, view here.
Large banking institutions are mostly restricted to making money with market making activities (which can be quite profitable for a bank using high frequency trading algorithms but less so for an individual trader).
You Should Not Make Your Earnings Public
If you become a profitable day trader, you should keep your earnings private as well. When you are using a profitable system, there will be many people trying to learn what you do, and how you do it. The more people who learn, the less money available for you (in most cases). If you don’t make money, you probably don’t want people to know that either. Simply put, there is no advantage to telling others how much money you make as a trader. If you want to publish your earnings, you are free to make whatever information public that you wish, but there is a good reason you will have a hard time finding any real traders who do this.