Markets think some sort of Brexit deal will be done

Even though the clock is ticking down towards the UK’s exit date from the EU at the end of this month, Brexit remains as clear as mud.
We still have no idea if a deal will be agreed at the mid-October EU summit, if a deal would then be approved by the UK parliament, or whether the UK government will seek, as mandated by law, an extension to Article 50 in the event of no-deal.