[Beginner] One 0.05 BTC long on Bitunix, placed three ways: Market vs Limit vs Trigger

Same trader, same idea, same size: a 0.05 BTC long on the BTCUSDT perpetual. At this morning's last price of 79,985.5 that is 3,999.28 USDT of notional. The only thing that changes below is the tab clicked in the order panel, and that one click decides your price, your fee and whether you get filled at all.

The image is the live Bitunix BTCUSDT futures page from this morning with the order panel on the Limit tab: Market / Limit / Trigger tabs, order price, quantity, TP/SL box, Time in Force GTC, and the VIP 0 rates of 0.0200% maker and 0.0600% taker.

A) Market tab You type a size, not a price. It fills right away against the best offers in the book. Fee: 3,999.28 x 0.0006 = about 2.40 USDT to get in. Catch: the final price can differ from the number on screen when the market moves fast.

B) Limit tab You type the price. It fills only at that price or better. Placed below the current price, a buy limit waits in the book; if it fills from there you pay the maker rate. Fee if it rests and fills: 3,999.28 x 0.0002 = about 0.80 USDT. Catch: if price never comes back, you have no position at all.

C) Trigger tab Nothing happens until price touches your trigger. Then Bitunix sends the Market or Limit order you set up in advance. Example of the mechanics only: a trigger buy at 80,819.4, today's 24h high, would sit idle until that print. If it fires as a Market order, 0.05 BTC at 80,819.4 is about 4,040.97 USDT and the taker fee about 2.42 USDT. Catch: Bitunix's own guide points out that reaching the trigger price is not the same as getting filled. If the order it sends is a Limit, it can still sit unfilled when price runs past it.

Round trip, both legs the same type:

• Market in, Market out: about 4.80 USDT
• Limit in, Limit out as maker: about 1.60 USDT

Contract facts (Bitunix public API): minimum order 0.0001 BTC, default leverage 10x, max 200x. One Market order is capped at 120 BTC while one Limit order can be up to 1,200 BTC. Mark price at the time was 80,007.9, 24h range 79,468.3 to 80,819.4.

What beginners get wrong most:

• Using Market for every entry, then wondering where the fees went.
• Placing a buy limit above the current price and being surprised it filled instantly.
• Treating a Trigger as a guaranteed fill.

Try it: open the Bitunix BTCUSDT page, switch between the three tabs without submitting anything, and watch which fields appear and disappear. Then do the same on ETH, SOL, XRP or DOGE; the fields are the same, the contract numbers are not.