There are a number of reasons I have personally invested into Stellar, in no particular order:
The Ripple and Stellar frameworks are forks of one another and historically we have seen that when one does well, the other does well too - I can't see that changing anytime soon in the near future
However, recently, we have seen that STR is able to stand by itself and its value has strengthened independent of XRP and my view is that STR is onto a bullish long-term path with very substantial upside potential!
Jed McCaleb is without a doubt a very smart guy! There are some rather negative posts on the internet regards the fiasco between Ripple and him etc. but I'm willing to give the guy a chance especially because of point 4 below
I sincerely love the idea of helping the under-privileged, unbanked people of the world. It would be a shame that we only think of enriching ourselves at the expense of others. The concept of Stellar is in direct opposition to Ripple’s world view (that of collaborating with the elite of the world and enriching the already rich). To me, the Stellar Foundation has some beautiful ethical values that I can fully support! Who doesn’t want a more equitable world where the poor are elevated and wealth can be re-distributed to a degree while at the same time elevating our standing also?
I unreservedly believe that banks, financial institutions and medium to large enterprises will come on-board in adopting Stellar in the near future as they see the world progresssively move towards digital assets (for example, L'Eco).
It is estimated currently there is approximately $60 Billion invested into the entirety of the crypto world. This figure is expected to rise to about $3000 Billion within the forseeable future. So any investment into alt-coins with substantial real use-cases such as Stellar will have tremendous uptrend in the medium to long-term