Algo trading != HFT. HFT is a type of algorithmic trading strategies, categorized by trading interval. In the same categorization there are mid-freq strategies

Algo trading != HFT. HFT is a type of algorithmic trading strategies, categorized by trading interval. In the same categorization there are mid-freq strategies as well. The term "high frequency" is rather subjective, it depends on what alpha you're targeting after.