tt_spec:
          "1S" | "5S" | "10S" | "15S" | "20S" | "30S" | "1M"  | "5M" 
     |    "10M" | "15M" | "20M" | "30M" | "1H" | "3H" | "4H" 
     |    "6H" | "8H" | "12H"