Unless you have a need for short term cash (emergency fund, home downpayment, new car) keeping cash is considered a loosing game in the long run.
In the short run, you are looking to get 3% interest on cash through the end of the year while hoping that the market doesn't return >3% by year end.
Speculation aside... the general consensus is that unless the cash is earmarked for short term spending, it's always better to invest according to your Asset Allocation for the long term.
Do you need the money in 6-12 months? Yes, keep it in cash.
Can the money sit for 5-10+ years? Invest it, yesterday already.
What your describing is a game people normally play with their emergency fund, or whatever cash they feel they must hold for their own comfort. If you are holding cash because you need it, then you can try and earn as much interest you can off bonus offers etc. If you have 1k to save every month, invest it.