How to flip Divine super defence potion(4) in OSRS

Flipping Divine super defence potion(4) on the Old School RuneScape Grand Exchange currently makes about 250 gp profit per item after the 2% GE tax: buy near 7,100 gp (the instant-sell price) and re-list near 7,500 gp (the instant-buy price).

• Buy at (instant-sell): 7,100 gp
• Sell at (instant-buy): 7,500 gp
• Margin after 2% tax: 250 gp (3.52% ROI)
• Buy limit per 4 hours: 2,000
• 24h volume: 9,587 (liquid)
• Max profit per limit cycle: 500,000 gp on 14,200,000 gp of capital

The flip, step by step

1. Place a buy offer at or just above 7,100 gp (the current instant-sell price).
2. Wait for the fill. Divine super defence potion(4) is liquid right now, so expect fills within the hour at reasonable prices.
3. Re-list at or just below 7,500 gp (the current instant-buy price).
4. The GE takes 150 gp tax (2%) per item when it sells, leaving 250 gp profit each.
5. Repeat up to the buy limit (2,000 per 4 hours), a full cycle is 500,000 gp on 14,200,000 gp of capital.

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