Efficient Markets Hypothesis $($LO$3,$ CFA$1)$ The Durkin Investing Agency has been the best stock

picker in the country for the past two years. Before this rise to fame occurred, the Durkin newsletter

had $200$ subscribers. Those subscribers beat the market consistently, earning substantially higher

returns after adjustment for risk and transaction costs. Subscriptions have skyrocketed to $10,000.$

Now, when the Durkin Investing Agency recommends a stock, the price instantly rises several points.

The subscribers currently earn only a normal return when they buy recommended stock because the

price rises before anybody can act on the information. Briefly explain this phenomenon. Is Durkin's

ability to pick stocks consistent with market efficiency?