I obeserved that the Option Chains for US Stocks (TSLA, AMZN ...) are sometimes late (especially on mondays). Last monday at 11:00 am there was still the volume and open interest from friday (eventhough the market was already open for a while which means that brokers like IB or TOS already had the data). I read that you receive your data from cisco. Is there a normal process that stops the new data from coming in on a regular monday? Is it normal that cisco delivers the data late on mondays?