Piper Jaffray analyst Stephanie Wissink points out that over her firm's 15 years of coverage, speculation of a merger between Hasbro (HAS) and Mattel (MAT) has surfaced several times. Hasbro's strong Q4 earnings report and share rally, in contrast with Mattel's negative Q4 preannouncement and pullback, has reignited the conjecture, Wissink tells investors in a research note. Economically a merger would create value, but a combination of the number two and three toy companies "would require significant evaluation from anti-trust authorities," the analyst writes. She believes a deal is possible if the Federal Trade Commission widens the boundaries around "youth entertainment & play," say to include video games, digital games and media. Hasbro closed yesterday up 67c to $94.98 while Mattel, after rallying in early trading, closed down 4c to $25.88. Wissink adds that she can find upwards of $500M of merger synergies if the two companies were to combine.