Why a big margin can be a bad flip
Thin volume, old prices, one-off trades and falling prices all make margins look bigger than they are. What to check before you buy.
Offerbook · Published · 4 min read
Sort any item list by margin and the top rows look amazing: items with spreads of hundreds of thousands of gp. Most of them are not flips. A margin is two recent trades, one on each side, and those two trades can say very little about what you will actually be able to buy and sell at.
One or two trades a day
If an item trades twice a day, its "margin" is the gap between two strangers' trades, maybe hours apart. Put in a buy offer and it may sit for a day. Put in a sell offer at the old high and it may never fill. A real flip needs other players trading the item steadily, so your offers fill on both sides.
Old prices
Every price on Offerbook shows how long ago it traded. A spread between a buy from five minutes ago and a sell from three hours ago is not a spread: the market has moved since. Offerbook hides a margin on its hub pages when either side is more than 2 hours old.
One odd trade
Sometimes a player sells far below the market by mistake, or buys far above it. That one trade shows up as a huge margin until the next normal trade replaces it. If the margin is much bigger than the item's usual range, assume it is one of these.
A falling price
When an item is crashing, its last buy can sit well above its last sell for a while, because sellers keep undercutting each other. That looks like a margin, but you would be buying into a fall.
What to check instead
- Volume per hour, so you know your offers will fill.
- Reliability, the share of the last 24 hours the spread beat the tax. A high number means the margin is a pattern, not an accident.
- Price age, on both sides.
- The 7-day range on the item page, to see if today's prices are normal.
This is why Offerbook ranks flips by what a 4-hour window can realistically make, not by margin. The list below is today's top flips with the two numbers that matter most next to the margin.
| Item | Margin | Reliability | Traded / hr |
|---|---|---|---|
| Elemental amulet | 37,501 gp | 43% | 183 |
| Diamond dragon bolts | 75 gp | 43% | 49,311 |
| Dragon crossbow | 4,791 gp | 69% | 412 |
| Dragon boots | 4,900 gp | 86% | 531 |
| Hallowfell | 14,884 gp | 61% | 113 |
Margins are after the 2% GE tax. Per 4h is margin times the quantity one buy-limit window can fill, sized to a 10m bankroll.
You can apply the same checks yourself on the Screener, which shows margin held and volume for every item, and on Today's flips. See also dumps vs crashes.
Offerbook is gp only and has nothing to do with real-world trading. Prices move, so nothing here is a promise of profit. Every trade is one you make yourself in game.