Lessons learned from the volatile 2018 market: - Paid services for real time data (e.g. QuoteVue) fail when you most need them to model the best way to manage your positions - Paid data for backtesting become unavailable for unknown reasons (OptionVue) when you most need them to recapitulate fast moving markets a few days back - Paid alert services tend to reduce content and communication when things don't work out as expected (CD; Kevlar definitely and RTT following through) - Recommended brokers change their margin rules when markets do not behave as expected - ... much more things to add, of course. Conclusion: Go your own way and wisely allocate your resources to what keeps working in tough situations. At least it will not require the effort to blame others for your errors. Said this, I learned a lot of useful staff from the CD community, but ended up with the sweet-sour feeling of having supported a business that has not succeeded in making reality its noble educational goals beyond its intrinsic vocation of making money for its promotors. Anyway, under these circumstances, it does not surprise me that CD will split up soon into a collection of spin offs.