【中文版】

为什么2015年的银行存款利率会如此低呢？这背后有多重因素共同作用。首先，当时全球经济形势并不乐观，中国经济也面临着下行压力。为了刺激经济增长，国家采取了宽松的货币政策，大量资金涌入市场，导致银行存款相对过剩，银行为了吸引客户，不得不降低存款利率。

其次，随着互联网金融的兴起，传统银行的存款业务受到了挑战。为了与互联网金融竞争，银行也需要降低存款利率，以吸引更多的客户。此外，国家还通过一系列政策来规范金融市场，保障金融安全，其中就包括了存款利率的调整。

不过，虽然2015年的银行存款利率较低，但这也为经济发展和金融市场的稳定创造了有利条件。低利率政策可以刺激投资和消费，促进经济转型升级，同时也有利于防范金融风险和维护金融稳定。

【英文版】

Why were bank deposit interest rates so low in 2015? There were multiple factors that contributed to this. Firstly, the global economic situation was not optimistic at that time, and China's economy was also facing downward pressure. To stimulate economic growth, the country adopted a loose monetary policy, which led to an influx of funds into the market and a relative surplus of bank deposits. In order to attract customers, banks had to lower their deposit interest rates.

Secondly, with the rise of Internet finance, traditional banks' deposit business was challenged. To compete with Internet finance, banks also needed to lower their deposit interest rates to attract more customers. In addition, the government also regulated the financial market and ensured financial security through a series of policies, including the adjustment of deposit interest rates.

However, although bank deposit interest rates were low in 2015, this also created favorable conditions for economic development and the stability of the financial market. Low interest rate policies can stimulate investment and consumption, promote economic transformation and upgrading, and also help prevent financial risks and maintain financial stability.