Perhaps this snippet from the article is a clue to why there has...

Perhaps this snippet from the article is a clue to why there has been share price weakness and a lack of institutional buying in Fluence.
‘The water sector is not an easy sector to invest into because of the high fragmentation of the industry and the very long-term time horizons that people (have to) take. So, while water obviously lends itself very much to impact investments, the viability very much depends on the time horizon a fund can take. If the time horizon is 3-6 years, it will not be easy to generate the returns a fund needs to cover both its costs and provide the investors with an attractive return. This, in particular, holds for investing into (early-stage) water technology companies. ‘