Kathleen Brooks, research director at spreadbetter City Index, mulls over with Proactive Investors the recent ascendency of the FTSE100 while the UK pound hits a fresh low.
On Tuesday, October 4 the index of leading shares broke through 7,000 while the UK currency hit the lowest level since 1985.
Brooks said Footsie appeared to be ignoring the uncertainty caused by Brexit "largely because we haven’t actually seen in the real hard economic data, those concerns actually come through".
FTSE100 hasn't caught up yet in the way that has been seen in other markets, like FX, she suggested.
It is also being boosted by gains from big oilers on plans by OPEC to cut production, she highlighted.
The weakness of the pound is largely due to worries over the so-called hard Brexit, where the UK withdraws from the single market.
"This conservative party conference has been a real sell for the pound this time round," said Brooks, who added that it appeared Prime Minister Theresa May, in comments, appeared willing to accept that the economy was going to suffer, if we withdraw from the single market