Consider APT model. The model, as discussed, is based on markets integration of news flow into valuations of the assets. In recent years, we have seen a massive proliferation of data sources being made available to retail investors. The quality of these sources varies widely. Many sources effectively aggregate and re-package the same information. To differentiate between themselves from competition, these platforms offer more analysis and commentary, often without clearly defining the boundary between data, reported information and subjective opinion of journalists and analysts working for these platforms). And many of these sources are paired with technological tools that allow faster and cheaper trading by retail investors.

In your opinion, what implications do these new (trading and information delivery) platforms have in terms of:

1) Ensuring markets efficiency (think of APT framework for pricing assets)?

2) Supporting markets stability (markets being more or less prone to fast crashes and trend reversals, markets having lower or higher liquidity risks)?