The game was developed by Bug-Byte Software and released in 1984 on the Commodore 64 and ZX Spectrum, around the same time as Ian Bell's and David Braben's Elite was released on the BBC Micro and Acorn. Unlike Elite the game used sprites for the enemy ships instead of wireframe models, it also featured a much simpler flight model, without the ability to roll the ship.
You play as the solar system's last space trader, after pirates have scared everybody else off. The game features a solar system with 8 planets which you'll trade between, encountering pirates to fight or bribe along the way, as well as the occasional random event.
There's also an 8 player hot-seat mode, where players take turns after each planetary visit.
Bug-Byte's Star Trader is unrelated to the 1974 game of the same name by Dave Kaufman, as well as Imagine Software's Star Traders, which also was in development for the C64 in 1984, but was cancelled before release.