STOCKS STAY PUT: Here's what you need to know

Stocks swung between green and red Wednesday, finishing largely unchanged after oil took a tumble and the threat of a possible government shutdown if no government spending deal is reached this week. 
Here’s the scoreboard:
S&P 500: 2,629.27 (-0.01%)
Dow: 24,142.01 (-0.16%)
Nasdaq: 6,776.38 (+0.23%)
Oil: $55.89 (-2.73%)
10-year treasury bond: 2.35% (-0.83)
UnitedHealth Group Inc said it would buy kidney care services provider DaVita Inc's medical unit for about $4.9 billion