From DBS Vickers:

Increasing AUM size is putting pressure on operation costs and redemptions as money market funds usually have to set aside 5-10% of assets as a liquidity reserve to prepare for redemptions. Looking at Yu'e Bao’s better liquidity due to support from Alipay, we assume a 5% reserve ratio to arrive at a liquidity reserve of Rmb25bn while daily average idle funding parked at Alipay is about Rmb30- 40bn. Yu'e Bao may hit the assets under management limit of Rmb1trn in the near term based on our estimates. In view of rising liquidity risks, Yu'e Bao announced in April that it will delay withdrawals of >Rmb50,000 to T+1 settlement if made before 5pm or T+2 settlement if made after 5pm. Other online money market funds such as Tencent’s Li Cai Tong or Baidu’s Baizhuan are also adopting T+1 settlements now.