(Bloomberg) -- The UK government bonds at the heart of recent market turmoil capped their biggest weekly surge on record. 

The rate on 30-year bonds has plummeted 72 basis points this week, its biggest retreat in data going back decades. The equivalent yield on 10- and 30-year inflation-linked gilts are also on course for record declines. 

The move reflects relief at the ousting of Prime Minister Liz Truss and her economic agenda. The market is also being supported by the exclusion of long-dated debt from the Bank of England’s bond sales program and signs that the pensions industry is on a more stable footing. 

Read more: UK Bond Traders Have a Warning for Conservatives Choosing New PM

Cash-strapped pensions were at the forefront of forced selling this past month when wrong-way bets on derivatives triggered calls to raise extra collateral. Both longer-maturity and inflation-linked debt are sought after by UK defined-benefit pensions, which need to match their assets with the timing of future payouts.

Still, traders were on edge on Friday as the Conservative leadership contest to succeed Truss as UK prime minister was in full swing. Speculation that former Prime Minister Boris Johnson would clinch the premiership was swirling, with traders distributing betting probabilities on group chats.

For some investors, the prospect of a contentious race, with divisive candidates potentially winning the premiership, raises the risk of renewed turbulence in already fragile markets. 

“Market participants after Truss was gone, got a little comfortable with the idea that the Tory party would choose a stable leadership -- clearly that still remains to be seen,” said Fredrik Repton, a portfolio manager at Neuberger Berman.

Read More: Mordaunt Bids to Lead UK by Showing Tories What They Missed 

The yield on 30-year gilts jumped 10 basis points on the day to just above 4%, close to levels before the mini-budget was announced in late September. 

--With assistance from James Hirai and Libby Cherry.

(Adds context, updates pricing.)

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