The majority of them lose at least half of their first invested capital in forex trading. This seems to be inevitable since you are paying for your tuition fees to the market in order to learn forex. When we first started out, there are so many things we do not know about. We want to avoid losing money. When we actually lose money, we are desperately looking to make back the amount lost that we took on more risk but we ended up losing even more money. Another reason is the fact that you know nothing about position sizes and what a certain position size amounts.
Brokers do not earn spreads only. It depends on what kind of model the brokerage firm adopts. For market makers, in most cases, your loss is their gain unless they hedge off your positions in the market. Brokers also earn from rollover fees. At times, when you check out the buy and sell rollover fees, you will notice that both columns are negative.
You can lose more than your equity. Do you remember the Swiss currency crisis in Jan of 2015? Because of huge movement in Swiss pairs, clients lose more than what they have in their accounts, resulting in negative equity. When such cases happen, your broker either waives off or you are asked to pay for whatever you owe. In view of this, please make sure if your broker offers negative balance protection.