I am trying to sell the Bid but my opening short sell order does not get filled. What is the red circle next to the stock symbol mean?

When you see the message "No opening trades: ineligible PINK stock" it means an opening order for that contract is not allowed, even if your account has trading permissions for US Penny Stocks.

Additional Information…

A stock may be subject to short sale restrictions for various reasons, including trading halts, an inability of the broker to locate shares to borrow beforehand and SEC Rule 201 (uptick rule). 

To determine whether a short sale restriction exists for a given security prior to entering an order, you would need to first add the symbol to a quote line on the TWS.  Restrictions associated with trading halts and the inability to secure a locate can be determined by adding the…

Any size stock order, even if it is not in a round lot increments, can be submitted using a MOO, LOO, MOC or LOC order type. When you SMART route an At-the-Opening or At-the-Close order type, it will be routed to that symbol's primary listing exchange and given to the Specialist. There is never a guarantee that the Specialist will have enough shares available to match all the Buy and Sell orders they receive for an opening or closing cross. Orders are filled on a priority basis with the earliest submitted Market-on-Open orders filled first. If there are any shares still available to cross, the marketable Limit-on-Open orders with the earliest time stamps are next in line. If your order did not get filled, then there were not enough shares available for all of the orders submitted for the Opening or Closing cross trade…

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…