<prompt> Human: TLDR Pretty much all of my current wealth is in cash, losing money in real terms. Im 31 and want to invest mainly in equities low cost index trackers mainly but cannot bring myself to invest now with world indices at all time highs - I know I cant time the market but also cant get over the fear that I will lose out big if I invest now! Help!Ive recently got myself into a reasonable financial position - no debts, a secure income and around 100,000 c. US120,000 in cash.Im 31 and so want to invest mainly in equities with a view to becoming financially independent within around 15 years. In addition to the lump sum above I see myself being able to saveinvest around 3-4,000 c. US3.5-5000 each month for the next 3-5 years, increasing around 50 after that.My main issue and its driving me crazy! is that pretty much all the main world indices are at all time highs which makes me extremely nervous about getting in at the moment. On the other hand Im getting around 0.1 interest on the cash i.e. losing money in real terms after inflation! which is very frustrating.I have read and understood all the advice about not believing you can time the market but I still find myself paralysed by the current market valuations and unable to pull the trigger and go for it!Ultimately I think Ill adopt a strategy whereby I split the lump sum into monthly investments over around 2 years in addition to contributing regularly from new savings - however even this approach doesnt sit well with me - I just feel like Im onto a loser if I invest at the moment!Usually Im a pretty rational person but I just cant seem to reason this one out and override my emotion to stay out! So Im after some more seasoned investors to put me straight!  <response>: I trust numbers more than intuition or emotions so here are some numbers for you to consider: Since 1910 the SP500 is at an all time high about 20 of the time. Total return for a buy and hold investor is 9.6 annualized. Total return for an investor who gets out of the market whenever it hits a new high is 6.5 annualized. The average return monthly return is 0.87. The monthly return following a new high is 1.33, and is 0.76 months that do not follow a new high. The average annual return over the year following a new high is 14.57, while the average return for the year following all other months 10.92. By avoiding being invested at new highs you are avoiding some of the best performing months and years in the market. Finally, if you do want to be a value investor you shouldnt just look at all time highs you should look at price multiples PriceEarnings, PriceSales, Price?. Based on such measures there are certainly other markets that are more attractively priced than US. If you dont like US because of high valuation, then you should at least consider other markets with more attractive valuation. Personally, I dont like to invest in value. For me its more painful to invest in beat down markets than to invest in a strong trending markets. Edit: One thing I forgot to add. Volatility for the buyhold and avoid-new-high investors was nearly identical: 15.03 and 14.47. So not only are the returns considerably better for buy-and-hold but also the risk-adjusted returns. 