How to flip Strength potion(4) in OSRS

Flipping Strength potion(4) on the Old School RuneScape Grand Exchange currently makes about 6 gp profit per item after the 2% GE tax: buy near 120 gp (the instant-sell price) and re-list near 128 gp (the instant-buy price).

• Buy at (instant-sell): 120 gp
• Sell at (instant-buy): 128 gp
• Margin after 2% tax: 6 gp (5.00% ROI)
• Buy limit per 4 hours: 2,000
• 24h volume: 193,697 (extremely liquid)
• Max profit per limit cycle: 12,000 gp on 240,000 gp of capital

The flip, step by step

1. Place a buy offer at or just above 120 gp (the current instant-sell price).
2. Wait for the fill. Strength potion(4) is extremely liquid right now, so offers at fair prices typically fill within minutes.
3. Re-list at or just below 128 gp (the current instant-buy price).
4. The GE takes 2 gp tax (2%) per item when it sells, leaving 6 gp profit each.
5. Repeat up to the buy limit (2,000 per 4 hours), a full cycle is 12,000 gp on 240,000 gp of capital.

Margins move constantly. Re-check the live Strength potion(4) numbers and price chart on GrandExchange.com right before committing.