What do you guys do with your 13th-month bonus?

Don't have now as current job not entitle to.

If I have, I would split to :
1) 10% to charity (2.5 time taxable income deductable or non deductable)
2) 70% to SRS (reinvest to Robo or Index fund or blue chips) or MA/SA top up (get 4%+ guaranteed)
3) 20% savings for future good investment and strike when see a good deal immediately.

Number 1 maybe good for tax planning if not for good purpose to give and sow a good seed. The rest is all for long and short term investment.

Depends if you got any committments (parents/house/car/child etc), if not allocate a portion for CPF RSTU SA top up, it does it bit to build you retirement fund plus tax relief for next year, do it yearly and it becomes a good rountine of retirement planning.

Investing is great if you have excess, time in the market is always better than timing the market.

$1k to build the baby's CDA, another $1k towards my CIMB account, the rest is in the savings account as I source for an apt gift for the wifey (probably a massage package because she has sore shoulders from having to carry the baby always) (becos as they say, Happy Wife, Happy Life :) )

Annual insurance premium payments.