How to flip Cosmic rune in OSRS

Flipping Cosmic rune on the Old School RuneScape Grand Exchange currently makes about 4 gp profit per item after the 2% GE tax: buy near 114 gp (the instant-sell price) and re-list near 120 gp (the instant-buy price).

• Buy at (instant-sell): 114 gp
• Sell at (instant-buy): 120 gp
• Margin after 2% tax: 4 gp (3.51% ROI)
• Buy limit per 4 hours: 18,000
• 24h volume: 18,007,197 (extremely liquid)
• Max profit per limit cycle: 72,000 gp on 2,052,000 gp of capital

The flip, step by step

1. Place a buy offer at or just above 114 gp (the current instant-sell price).
2. Wait for the fill. Cosmic rune is extremely liquid right now, so offers at fair prices typically fill within minutes.
3. Re-list at or just below 120 gp (the current instant-buy price).
4. The GE takes 2 gp tax (2%) per item when it sells, leaving 4 gp profit each.
5. Repeat up to the buy limit (18,000 per 4 hours), a full cycle is 72,000 gp on 2,052,000 gp of capital.

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