Server-side OCO and bracket orders: which platforms really support them for discretionary scalps?

[FXS London Scalper]

I want a simple thing: enter, and have a stop and target that cancel each other on the server, not on my PC. Sounds basic. In practice it depends a lot on the platform and the broker setup.

What I've found so far, please correct me if your experience differs:

• MT4/MT5. SL and TP attached to a position are held server-side, so that part works. A true OCO between two pending entries is not native. You need an EA, which means your terminal or VPS has to be running.
• cTrader. Protection orders sit on the server and advanced take-profit with partial levels is built in. For manual scalping this has been the cleanest for me.
• Broker web terminals. Mixed. Some support brackets on entry, some silently drop the TP when you modify the stop.

The trap I fell into: an "OCO" script on MT5 that worked perfectly until my VPS rebooted for updates. The breakout entry triggered, the opposite pending order was never cancelled, and I ended up with two positions in opposite directions during a fast move.

So my rule now is that anything that has to happen while I'm not watching must live on the server. Everything else is a convenience.

What do you use for bracket entries, and has anyone tested how their broker handles modifications during high volatility?

[Amanhasnoname]

The VPS reboot story is painfully familiar. I had almost the same thing happen with a straddle EA before the US open on USDJPY, except in my case the platform froze rather than rebooted. One side filled, the other pending order sat there untouched, and price whipped back through it about forty seconds later. I spent the next few minutes closing a hedge I never meant to own while the spread was still wide.

These days I use cTrader for anything bracketed and keep MT5 only for the attached stop and target on a single position. The one thing I tested before trusting it was a modification during news. I moved the stop on a small EURUSD trade three times in the minute after CPI and checked the order history afterwards. The target stayed intact every time, which was not the case on a broker web terminal I tried last year.

If you must stay on MT5, I would skip the two-pending OCO entirely and place a single stop entry with protection attached, then decide the other side manually.