According to the Athens Exchange Rulebook there are 3 trading categories for all stocks. Each stock, based on its trading statistics and financial position, is traded only in one of these categories.
 

• Main Market

Trading hours
10:30 – 17:20 (17:05 – 17:20 at the close price)
 

• Low Dispersion / Surveillance / Under Deletion

Trading hours
11:58 – 12:00, 13:43 – 13:45, 15:28 – 15:30, 17:08 – 17:10 (17:00 – 17:20 at the close price)
 

• ETF

Trading hours
10:30 – 17:20 (17:05 – 17:20 at the close price)
 

• Alternative Market

Trading hours
11:00 – 17:00 (17:00 – 17:20 at the close price)