Perpetual contract: A futures contract that is leveraged and never expires. Due to its lack of expiration, it carries a funding rate.
Funding rate: The rate that is exchanged between longs and shorts on perpetual contracts. If funding is positive, then longs will pay shorts and if funding is negative, then shorts will pay longs.
Spot: A spot market is one in which the delivery of the asset is immediate. This means that if you sell BTC/USD at spot, you are receiving USD in your wallet, you are not taking a short position.
Basis: The % difference between the spot and perpetual price.
Market-Neutral: Going long and short on the same asset, using different instruments and/or exchanges to do so.
Long basis: Going long on spot and short on the perpetual contract of a cryptocurrency.
Short basis: Going short on spot and long on the perpetual contract of a cryptocurrency.
Index price: The index price of each asset is the average of price of a specific asset on various exchanges.
Mark price: The current price of the future, calculated by using the best bid, best offer, and last traded price.
Liquidity: The ability to easily transact on an asset. If a coin is illiquid, it can be hard to enter and exit at optimal prices.
Margin: What you use as collateral in a leveraged position.