RadioShack’s stock closed below $1 a share on Friday for the first time in its history, reflecting investors’ concern over what lay in store for the long-struggling consumer electronics chain. Shares of RadioShack fell 11 cents, or 10 percent, to close at 92 cents — well below its nominal high of $79.50 from December 1999. The New York Stock Exchange can delist a stock if it closes below $1 a share for 30 consecutive trading days. Analysts say that a bankruptcy proceeding is possible. David Tawil, co-founder and portfolio manager of Maglan Capital, said, “I don’t think anybody will miss RadioShack if it goes out of business.”