The week's winners
Atrium up 7.1%
Goshawk up 5.4%

The week's losers
Royal & SunAlliance down 6.5%
Allianz down 5.5%

Insurers are doing well right now. But some are doing better than others.

Berkshire Hathaway is a case in point. With the steady hand of the world's second richest man, Warren Buffet, on the tiller, the insurance-based group reported a doubling in profits in the second quarter.

The group made much of its money from selling

US government bonds, but there's a lesson to be learned from breaking down its figures.

Profits from insurance underwriting alone totalled $260m (£162m) in the second quarter, against a loss of $16m (£10m) in the same period last year.

Net earnings per share boomed to $1,452 (£906) a share, up from $681 (£425) in the prior period.

The bumper results sent the shares rocketing into the stratosphere. The price was up by $200 (£125) a share on Friday's announcement and new investors would have to shell out an astonishing $75,300 (£46,964) to buy one share based on prices earlier this week - a result of there being relatively few of them on the market.

Chaucer's stock may not be rising by $200 a share but it continues steady growth. Enough to catch the eye of some significant institutional investors. Artemis Investment Management bought a 3.4% stake, when the stock was at about 43p, taking its total holding to 14.14%.

Scottish Widows also bought in, acquiring 0.87% and taking its total stake to 4.32%.