Answer: ooos

AnswerCrossword Clue
OOOSSome tic-tac-toe winners
OOOS'XXX's and --' (Trisha Yearwood country hit)
OOOSAdd these to go from millionaire to billionaire
OOOSThey turn millionaires into billionaires
OOOSWhat's needed to go from millionaire to billionaire
OOOSThey turn millionaires into billionaires?