Ether futures serve the same institutional purpose as bitcoin-futures — regulated exposure without custody — and the ETH/BTC ratio is traded as an intercommodity-spread between the two, sized by notional rather than contract count.
Ether's supply mechanics and staking yield give it a different carry profile from bitcoin: holders of spot ether can earn staking rewards, which pushes the futures basis structurally lower than bitcoin's for the same level of demand.
Example: ether at $3,000 makes one standard contract $150,000 and one micro $300. A trader wanting a balanced ETH/BTC ratio spread against one 5-BTC bitcoin contract at $60,000 ($300,000) needs two ether contracts.
Related: bitcoin-futures, bitcoin-reference-rate, intercommodity-spread, staking, micro-futures