Eli purchased stock in XYC, Inc. at \$31 a share, but the stock is now worth only \( \$ 19 \) a share. Eli believes that XYC's stock will underperform the average stock market return going forward. However, Eli won't sell his stock until it reaches at least \( \$ 31 \). Eli's decision making is:
biased by sunk costs.
economically rational.
biased by self-control problems.
the result of hyperbolic discounting.