The following chart shows the average monthly out-performance of the FTSE 100 Index over the S&P 500 Index for the period 1984-2013. For example, the FTSE 100 Index has out-performed the S&P 500 Index by an average of -0.6 percentage points in January.

NOTES

1. Although since 1984 the S&P 500 has overall greatly out-performed the FTSE 100 (+1021% against +575%), there are months in the year when the FTSE 100 fairly consistently out-performs the S&P 500.
2. The five months that are relatively strong for the FTSE 100 are: February, April, July, August and December. For example, the FTSE 100 has out-performed the S&P 500 in February in 13 of the past 15 years.
3. The greatest monthly difference in performance is seen in May, when the S&P 500 on average beats the FTSE100 by 1.3 percentage points each year.

Data

The table below shows the monthly out-performance of the FTSE 100 Index over the S&P 500 Index since 1984. For example, in January 1984, the FTSE100 increased 6.3%, while the S&P 500 fell -0.9%; the out-performance of the former over the latter was therefore 7.2 percentage points.

The cells are highlighted if the number is negative (i.e. the S&P 500 out-performed the FTSE 100).

 FTSE 100 v S&P 500(£)

The following chart is similar to the above except the S&P 500 monthly returns have been currency-adjusted into sterling returns.

An effect of adjusting for currency moves is to amplify the out-performance of the FTSE 100 index in certain months (April, July, and December). Conversely, the FTSE 100 under-performance is amplified in January, May and November.

Whereas before the relatively strong FTSE 100 months were February, April, July, August and December, we can see that the currency-adjusted strong months are just April, July, and December.