The advantage of using Atomic.Finance covered call strategy is there's a potential for higher profit (7.87% APY historically), whereas joinmarket liquidity is < 1% APY IIRC.

The downside is you take on more risk. There's the chance that Bitcoin price goes above the strike price and you end up with less Bitcoin. However this strategy is quite conservative, and the historical max drawdown was 1.14% for a single trade.

Generally, this strategy works by using TA filters to see market trends, and sell a call during a downtrend, and do nothing during a price upswing.