I have about a $150k lump sum to invest, but am looking for a short term investment as I need the capital back in 4-5 years. Any recommendations on where I should park it/invest in?

Though your post is more than a year old, you may still consider investing some of it here: https://ukglobalinvestors.com/asia/singapore/

If you are going for stock market investing, dont invest lumpsum.

Use DCA buy every month to average out the price of the stock.

Buying mutual funds is a good place to park your money :)