sincere question: trading large lot sizes in a live account?

hey I've been aggressively scaling up my live trading account and have recently
started placing 27, 28, 33, even 35 lot trades in a single order. So far there has been no discernible slippage with Oanda.
The way things are going and if I add more funding (my wife's funds) I can foresee placing 50, 60, even 90 lot trades or more.
I am not used to these kinds of lot sizes and have some questions.
At what point do you start getting slippage?
I don't do prop firm challenges any more but remember suffering horrific 5 pip slippage on a 20 lot EURAUD trade with one of these firms.
Most brokers cap you at 100 lots in a single order, don't they?
Do you have to break up 100+ lot orders in chunks before placing them?
If so is there an EA that you recommend for breaking up the order into smaller chunks?
Are there any other gotchas you've experienced with large lot sizes that are not common with small lot sizes?

Since you are from the US and restricted to 50:1 leverage, with the money you have to have in your account, you might be better off trading in the stock/options market than currency market.

For 35 full sized lots of, say EUR/JPY, your margin requirement is slightly over $75K, and at 90 lots it is nearly $200K. That's a lot of money to be required in your account just to PLACE the trades, much less trade multiple pairs at the same time. Granted, at $900/pip you can make money quickly, but you can also get a healthy drawdown (a 17 pip move against you translates to over a $15K loss).

I never traded more than 10 lots at a time for those very reasons and that's with 400:1 (I stopped trading currency full time when we went back to 50:1 just due to the amount of money needed in the account). I didn't experience any slippage because I very seldom closed a trade manually.

Just be careful trading such high lots, because news and events can spike a pair against you quickly and enough to really hurt financially. Heck, a margin call at 80% is only about 60 pips, and they close your trades for you!

Good luck and I hope you become a very wealthy trader!

Great trading! The max lot size I trade is 50, but mostly I trade 20-40. Not had a problem with these numbers.

Placing multiple trades would help I guess. Also, have you looked into copy trading with different brokers, to spread things out a bit?

Saying that, if you don't have any problems with those sizes, just keep going. Remember, brokers make money when you trade so there's not much incentive for them to force you to move your account elsewhere.