How to flip Onion seed in OSRS

Flipping Onion seed on the Old School RuneScape Grand Exchange currently makes about 1 gp profit per item after the 2% GE tax: buy near 3 gp (the instant-sell price) and re-list near 4 gp (the instant-buy price).

• Buy at (instant-sell): 3 gp
• Sell at (instant-buy): 4 gp
• Margin after 2% tax: 1 gp (33.33% ROI)
• Buy limit per 4 hours: 600
• 24h volume: 364,817 (extremely liquid)
• Max profit per limit cycle: 600 gp on 1,800 gp of capital

The flip, step by step

1. Place a buy offer at or just above 3 gp (the current instant-sell price).
2. Wait for the fill. Onion seed is extremely liquid right now, so offers at fair prices typically fill within minutes.
3. Re-list at or just below 4 gp (the current instant-buy price).
4. The GE takes 0 gp tax (2%) per item when it sells, leaving 1 gp profit each.
5. Repeat up to the buy limit (600 per 4 hours), a full cycle is 600 gp on 1,800 gp of capital.

Margins move constantly. Re-check the live Onion seed numbers and price chart on GrandExchange.com right before committing.