How to flip Ancient brew(3) in OSRS

Flipping Ancient brew(3) on the Old School RuneScape Grand Exchange currently makes about 21 gp profit per item after the 2% GE tax: buy near 1,243 gp (the instant-sell price) and re-list near 1,289 gp (the instant-buy price).

• Buy at (instant-sell): 1,243 gp
• Sell at (instant-buy): 1,289 gp
• Margin after 2% tax: 21 gp (1.69% ROI)
• Buy limit per 4 hours: 2,000
• 24h volume: 39,574 (very liquid)
• Max profit per limit cycle: 42,000 gp on 2,486,000 gp of capital

The flip, step by step

1. Place a buy offer at or just above 1,243 gp (the current instant-sell price).
2. Wait for the fill. Ancient brew(3) is very liquid right now, so offers usually fill within minutes to a quarter hour.
3. Re-list at or just below 1,289 gp (the current instant-buy price).
4. The GE takes 25 gp tax (2%) per item when it sells, leaving 21 gp profit each.
5. Repeat up to the buy limit (2,000 per 4 hours), a full cycle is 42,000 gp on 2,486,000 gp of capital.

Margins move constantly. Re-check the live Ancient brew(3) numbers and price chart on GrandExchange.com right before committing.