What is an Alternative Trading System (ATS)?

For security reasons, IBKR does not allow the ability to disable the Secure Login System for Client Portal access or for the trading platforms…

The electronic venues for bond trading are generally formed as an ATS which seek to match buyers and sellers but do not impose an obligation on the liquidity providers to post firm quotes or to fill an order. Instead, a quote displayed on an ATS serves as an "indication of interest" and not a firm commitment to buy or sell…

No, IBKR will not be paying interest on cash held in an ISK account, but you can get interest on your cash in your linked trading/general investment account (GIA). …

In the IBKR trading platforms you simply enter a buy or sell order and the IBKR system marks your order as an opening buy or sell or a closing buy or sell. As an example, create a short sell order in the IBKR trading platform and IBKR checks the account's position and marks the order as an opening or closing order.  Note that IBKR does not allow clients to simultaneously maintain both a long and short position in a given instrument, any order to sell (buy) will only result in a short (long) position to the extent the order quantity exceeds any existing long (short) position held and which would then be closed by execution of that order…