Bond markets continue to get busier as more companies announce buybacks and raise funds to fund them. Rio Tinto last week followed up its offer to buy back notes with a new debt issue to fund the offer. The company said US$1.91 billion of the notes were validly tendered, leaving US$587 million of debt still outstanding. To fund the buyback, Rio Tinto sold US$2 billion, comprising of US$500 million each of five-year and 30-year debt, and US$1 billion of 10-year notes.The yield was slightly better than expected, benefitting from an upgrade in rating from Moody's, which raised the rating to A3 from Baa1. The yields were set at a spread to 68, 93 and 115 basis points over similar term Treasuries for five, 10 and 30-year debt respectively. Paladin Energy raised US$300 million, through the issue of 3.625 per cent 2015 convertible bonds, to fund a buyback of up to US$250 million of December 2011 convertible bonds, with the balance being for expansion plans.Citigroup Australia is buying back A$1.3 billion of June 2012 government guaranteed bonds and will use the auction method to get bids from bond-holders.Western Areas, a nickel producer, sold $110.2 million of 2014 convertible bonds at a coupon of 6.375 per cent, using the proceeds to buy back $103 million of eight per cent 2012 bonds.Dexus Wholesale Property Fund made its first bond sale to repay loans, raising $250 million, via 2015 notes, at a 185 bps spread over the swap rate. Goodman Group is the next property company planning a bond sale.Among banks, National Australia Bank raised $1.35 billion, comprising of five-year fixed rates notes, totalling $550 million and $800 million of floating rates notes at a spread of 120 bps.Meanwhile, the attractiveness of Australian debt is growing because of expectations the currency will gain further. Hedge Fund Thames River Capital is reported to have invested half of its $2 billion global fund assets into debt in Australia, Brazil and South Africa, without hedging against a possible fall in their currencies.