Silver broke above $30 an ounce as the precious metal took center stage in the retail investor frenzy sweeping through markets, fueling a debate over the power of Reddit-inspired speculators to take on ever-bigger targets. Most-active futures jumped as much as 13% to $30.35 an ounce on the Comex, after a weekend buying binge that overwhelmed online sellers of silver coins and bars from the U.S. to Australia. BlackRock Inc.’s iShares Silver Trust, the largest exchange-traded product tracking the metal, recorded an unprecedented $944 million net inflow on Friday.