SPEX can be bought on a constantly updated list of exchanges (please refer to the SPEX page on CMC for an updated list) or can be received as a reward for providing liquidity and staking.
The fundamental use of Step Ex's governance token SPEX is yield farming. That provides:
Non-inflationary pools, where rewards are market-bought,
Truly liquid pools, where the staked amount remains liquid,
Fair income distribution: it increases with the time of stake.