4. Three years ago, Adrian purchased 100 shares of stock in X Corp. for $10,000. On December 30 of year 4, Adrian sells the 100 shares for $6,000. On January 20 of year 5, Adrian purchases 100 shares of X Corp. stock for $6,000. How much loss from the sale on December 30 of year 4 is deductible on Adrian's year 4 tax return? What basis does Adrian take in the stock purchased on January 20 of year 57