SoftBank Group Corp. resumed buying back shares in September, shelling out 40.1 billion yen ($0.52 billion) after suspending in August a multi-billion-dollar program that’s proven instrumental in buoying the stock.

Masayoshi Son’s conglomerate bought back 6.17 million shares last month, it said in a filing Wednesday, part of a now half-completed 2.5 trillion yen buyback program. The firm halted that in early August, about a month before announcing a deal to sell U.K. chip designer Arm Ltd. to Nvidia Corp. for $40 billion.

The Japanese company resumed buying on Sept 15, the day after unveiling that mega-deal, then bought on every single business day till the final five days of the September quarter, when it’s prohibited from doing so. Despite the flurry of purchases, its shares are still down 2% over the month, after news emerged that the company was trading tech options, a strategy some investors deemed risky.

See: Nvidia to buy SoftBank's chip division for US$40 bil

Still, SoftBank’s stock is at two-decade highs, bouncing back after a year of coronavirus setbacks and losses at startups such as WeWork. It’s more than doubled from its March Covid-19 trough, aided also by plans to offload 4.5 trillion yen in assets -- an effort SoftBank is on track to surpass.

It’s so far only spent roughly 1 trillion yen of its envisioned share repurchase amount. As of September, it had used just a fraction of the 500 billion yen it pledged in a program decided on Jun 25. It also hasn’t launched a 1 trillion yen buyback plan the board agreed upon on Jul 30. SoftBank acknowledged in July it might not complete the buybacks by its originally scheduled target of Mar 31, the end of its fiscal year.