The main function of the HHI is to monitor the performance, and to highlight the attractiveness, of life sciences investments over the long term, and to try to identify those stocks that have disruptive technologies that consistently allow them to outperform both the index and the markets. Many of the 53 constituents of the index are high-risk, still being in the development stage, with micro-capitalisations and a long way from sales and profitability. Despite this, some companies can still make extremely attractive returns for investors, as evidenced by the top-performing stocks in 2021, Futura Medical (FUM) and e-Therapeutics (ETX), which both saw their share rise by over 150%