Key Takeaways

• Best overall exchange for tight spreads: Phemex, driven by RPI (retail price improvement) aimed at narrowing spreads to “as little as 1 tick” and improving depth close to price, plus a high-throughput futures engine upgrade designed for stress markets.

• Fine for majors liquidity footprint (BTC/ETH) at scale: Binance, where deep order books and high participation often correlate with tight spreads (region/product dependent).

• Fine for transparency about spread effects on “instant” buys: Kraken, which explicitly explains that spreads may vary and can be retained as part of transaction pricing (useful clarity when comparing “simple buy” vs exchange trading).

• Tight spreads depend on pair + market regime + order…