The Invisible Power of MacHines Revisiting the Proposed Flash Order Ban in the Wake of the Flash Crash

Technological innovation continues to make trading and markets more efficient, generally benefitting market participants and the investing public. But flash trading, a practice that evolved from high-frequency trading, benefits only a select few sophisticated traders and institutions with the resources necessary to view and respond to flashed orders. This practice undermines the basic principles of fairness and transparency in securities regulation, exacerbates information asymmetries and harms investor confidence. This iBrief revisits the Securities and Exchange Commission\u27s proposed ban on the controversial practice of flash trading and urges the Securities and Exchange Commission and the Commodity Futures Trading Commission to implement the ban across the securities and futures markets. Banning flash trading will not impact high-frequency trading or other advantageous innovative trading practices, and will benefit all market participants by making prices and liquidity more transparent. In the wake of the May 6, 2010 flash crash and the passage of the Dodd-Frank Wall Street Reform and Consumer Protection Act, now is an opportune time for the Securities and Exchange Commission and Commodity Futures Trading Commission to implement the ban

Avoiding perceived past resource use of potential competitors affects niche dynamics in a bird community

Background: Social information use is usually considered to lead to ecological convergence among involved con-or heterospecific individuals. However, recent results demonstrate that observers can also actively avoid behaving as those individuals being observed, leading to ecological divergence. This phenomenon has been little explored so far, yet it can have significant impact on resource use, realized niches and species co-existence. In particular, the time-scale and the ecological context over which such shifts can occur are unknown. We examined with a long-term (four years) field experiment whether experimentally manipulated, species-specific, nest-site feature preferences (symbols on nest boxes) are transmitted across breeding seasons and affect future nest-site preferences in a guild of three cavity-nesting birds. Results: Of the examined species, resident great tits (Parus major) preferred the symbol that had been associated with unoccupied nest boxes in the previous year, i.e., their preference shifted towards niche space previously unused by putative competitors and conspecifics. Conclusions: Our results show that animals can remember the earlier resource use of conspecifics and other guild members and adjust own decisions accordingly one year after. Our experiment cannot reveal the ultimate mechanism(s) behind the observed behaviour but avoiding costs of intra-or interspecific competition or ectoparasite load in old nests are plausible reasons. Our findings imply that interspecific social information use can affect resource sharing and realized niches in ecological time-scale through active avoidance of observed decisions and behavior of potentially competing species