Equity and interest rate usually have negative relationship so in an environment of raising interest it is wise to put money in bank and wait for a more suitable time to purchase stock. That time is usually when you see the central bank/fed has an intention to lower the interest or pump money into market.
Another solution of buying indexed fund without considering timing is to buy a portion of your money each year. For example, 10% of your money is invested right now and then another 10% next year,... and following that rule until you disburse out all of your money.
It should be to remember that investing is a longtime story , that is at least 10 years, if not saying dozens of 10-yr, to avoid cycle of economy. If your investing of period is shorter, just some years, you should think about the term of trading, not investing. It is sure that trading is not for common people, it requires time and experience and not for saving money, bearing low risk tolerance.