The Grand Exchange prices every tradeable item once per game update. A trade's margin is the gap between what buyers pay and sellers ask — small gaps on high-volume items are where steady profit lives.
Every item has a buy limit per 4-hour window; limits cap how much of one item you can flip at once. Alchemy values set a floor: when a nature rune costs less than the gap between an item's price and its high-alch value, alching prints coins — [the check runs live](/tools/alch-check).
High-volume examples
- Spirit shards — 24, limit 500,000, high-alch 15.
- Feather — 11, limit 100,000, high-alch 3.
- Chronotes — 288, limit 50,000, high-alch 30.
- Fire rune — 38, limit 25,000, high-alch 3.