Buying second rental property

[Ammar Muhammad]

Hello,

I have one rental property in Delaware (about 250K and monthly payments are 1.5K). I am not cash flow positive with this property since I got 15 year mortgage (my mistake, I should have done 30 yr mortgage :)). I am thinking about buying another rental property. Thinking about Philly or Delaware area for around 350K and estimated monthly payments will be about 2K. I have been reading a lot about having 6 month reserve for each rental property. I have 6 month reserve for my existing property (about 7.5K). My question is do I need to ensure that I can have 6 month of reserve for my second rental property as well before buying it? Want to understand what is a safe and general rule of thumb.

Also do people usually keep the reserve in cash or put then in some type of financial instruments. I feel like if I put them in ETFs, those can go down too. Furthermore do people usually combine the emergency fund with the rental property reserve or is it better to keep them separate?

Thanks