Three factors were at play: demand growth, robust retail investment, and falling supply.
On the demand side, sales of silver bars and coins rose by 20%, the largest driver was silver bar demand, which jumped 53%. Silver jewelry demand moved up 4%, to 212.5 million oz. Demand for industrial silver fell 1% to 578.6 million oz., due to a 9% drop in silver used in photovoltaic.
Silver supply fell by 2% last year, the third consecutive annual decline to 855.7 million oz. The largest downturn was experienced by primary silver mines, which decreased by 7% to contribute 26% of total mine supply. The zinc-lead sector contributed 38% of by-product silver, followed by copper at 23% and gold at 12%.
The price of silver also declined by 7.8% to average $15.71 in 2018. Negative factors affecting the price last year included a rising US dollar, interest rate hikes, the trade dispute between the United States and China, and lower global economic growth projections.