With the current bull market now the longest in history and the S&P 500 reaching an all-time high this week, we thought it would be a good time to check in on our market fair value.

This metric shows how big of a gap, on average, we see between market prices and our estimate of intrinsic value across the entire market or a specific sector.

The current ratio for all rated stocks is 1.02. This indicates that the market is slightly overvalued. That compares to a 52-week high of 1.11 seen in January and a 52-week low of 0.97 reached in April.

There isn't a large gap in average valuations by sector. The most overvalued is technology at 1.06 - that's 6 per cent above our estimates. The industrials, consumer cyclical, and basic materials sectors are close behind, looking 4 per cent overvalued.

The most undervalued sector is communications services at 0.96 - that's 4 per cent below our estimate of intrinsic value. Some of our top picks in the communications services sector include Comcast, China Mobile, and BT Group.