I've seen 100 and 1000 lot max size on retail accounts but if you honestly need more than that then I would suggest contacting your broker and moving to a professional account if eligible. You will no doubt get a higher limit but will forfeit protections such as negative balance prevention.
If you can't spot the liquidity then you are the liquidity.
I believe that you don't really needs to search for a broker with the highest lot size. It means nothing actually, I think that traders have to pa yattention to other details when they're choosing a broker, because there are lots of other things which are considered to be more relevant for traders. No doubts, that all traders try to find a broker according to their own needs, however the lot size doesn't matter at all. Of course, you can have your view on this matter, I just explain my own point of view, but I never pay attention to such details when I choose a broker.
I believe trading conditions matter more than the lot size. If a broker is having tight spreads and low commissions, then you can definitely good ahead. Fxview, tickmill and pepper are a few good ones in this regard.
HIGH RISK WARNING: Foreign exchange trading carries a high level of risk that may not be suitable for all investors.
Leverage creates additional risk and loss exposure. Before you decide to trade foreign exchange, carefully consider your investment objectives, experience level, and risk tolerance.
You could lose some or all of your initial investment. Do not invest money that you cannot afford to lose. Educate yourself on the risks associated with foreign exchange trading, and seek advice from an independent financial or tax advisor if you have any questions.
Any data and information is provided 'as is' solely for informational purposes, and is not intended for trading purposes or advice.
Past performance is not indicative of future results.