When you sell, there is a commission you do not receive the gross amount of a trade
In North America there is a thing called "the settlement date" this is when all trades are posted to your account
So when you sell, the money is do you on the settlement date, not the day of trade or the day after
First, buying ad selling stocks also have to pay taxes. And even it was a direct investment (you buy company's stocks yourself, like you go to Walmart and say, I want to buy 3 stocks) OR go through broker... you have to pay fees.
Many times, the trading system is not automatic. Trading stocks almost always have a middle person.... so when you purchase or sell the stocks, you will have to wait for the middle person to carry out your command. It is like you buy goods through ecommerce like Amazon... you place an order, and the staff will take the products and ship to your house...the staff is the middle person in this case. AND also you pay the company too... for example if you sell stuff on Amazon, there are fees that you need to pay. Even if your price is 600 dollars, you will not going to get 600 dollars exactly... so the trading stocks is like that too.
Depends on which stocks you bought - if you bought penny stocks, there tends to be little market for them in which case, there may have been no buyer for your stocks at the $123 price. Second, there is always going to be commission, so you probably lost $14 - $20 for buying and selling. Third, there is the bid/ask spread which tends to be high on penny stocks due to the illiquidity - this means that the price you were quoting may have been the ask price (the price someone would have sold at) - the bid price (the price someone would buy at) is always lower and on illiquid stocks, can be much lower (I have seen 50% swings in one day on illiquid stocks).
First of all - I don't believe you.
But second of all - my advice to you is to stop what you are doing, and instead learn about what it is you are trying to do.
I'm trying to learning how stock market works. I started with $50 with Tdameritrade and bought some stocks with it and in 3 months the $50 grew to $123. When I sold it I receive $97. How come? why did I lose so much? Also, it took couple of days for me to get my money so I can invest again. I thought with buying and selling, it's a rather quick process. So why did it take couple of days? Is it always like that? Any other advice would be great. Thanks