Valentine's Day may be a great day for couples but it certainly wasn't for the FTSE100 index. Last Tuesday it dropped to 5,892 after closing 53 points up the day before. Find out why here.

By Ed Towner

It may have been the day of love, but last Tuesday there was nothing but horror on the trading floor as the FTSE100 index dropped dramatically due to the UK credit warning.

Monday evening saw the downgrading of six eurozone countries; Italy, Malta, Portugal, Slovakia, Slovenia and Spain, while Moody's credit rating agency also warned AAA-rated Austria, France and the UK that their positions are not set in stone.

On Monday 13 February the FTSE100 closed up 53 points at 5,906 before dropping to 5,892 on the Tuesday following the report.

This move reflects the lack of love and feeling in the markets on Valentine's Day and traders' concerns haven't gone away as they seem to be investing with some caution ahead of the decision on the Greek position in the eurozone.

In the week leading up to Valentine's Day customer buying was on the increase, with a 10% rise in week-on-week equity investment and 15% more stock being bought than sold that week, TD Investing data show.

According to Stuart Welch, chief executive of TD Direct Investing, exploration companies are the main source of interest this year judging by how much interest they are attracting from investors.

"Gulf Keystone Petroleum, which tops our tables this week accounts for 26% of the buys and 21% of the sells. The AIM-listed oil explorer's followers will have seen its shares more than double since the start of the year, and its market capitalisation now reaches well over £3bn."

"The company has been causing some excitement with its latest exploration well and there has been much talk that it could attract attention from larger groups such as ExxonMobil."