Crystal Ball Trading Game

Limits of News-Based / “Crystal Ball” Trading

• Many note that knowing headlines a day in advance is often not enough; markets may have already priced in expectations.
• Reaction to news is path-dependent and context-heavy (consensus, expectations, macro backdrop), so the same headline can lead to up or down moves.
• Some argue the experiment’s “crystal ball” isn’t really clairvoyance: you see partial information, not actual future prices.

Leverage, Risk, and Position Sizing

• Overuse of leverage is highlighted as the main failure mode in the game.
• Several posters bring up Kelly criterion and “log optimal” sizing, but others say Kelly overestimates bet size in noisy markets.
• Going 10x or 50x on index moves is criticized as unrealistic and suicidal in real markets.

Indexing vs Active Trading

• Repeated advice: if you don’t have a real edge, just buy broad index funds (e.g., S&P 500) and hold.
• Some experiment with always-long or always-short S&P strategies in the game, showing that leverage and date selection dominate outcomes.
• Discussion that “buy and hold” with dollar-cost averaging can outperform attempts at timing, even with hypothetical perfect dip timing.

Insider Knowledge and Legality

• Debate over using work experience at a pre‑IPO or early public company as an edge.
• Clarification that legal “insider trading” (insiders trading their own stock under plans) differs from illegal trading on nonpublic material information.
• Some insist that trading based on internal all‑hands knowledge would be illegal.

Market Structure, HFT, and “Cheating”

• Debate over whether success requires being “first, smarter, or cheating,” and whether “cheating” is effectively necessary.
• Explanations of high‑frequency trading, payment for order flow, and latency arbitrage; disagreement on whether this constitutes front‑running or is even advantageous.
• Some argue you only need to be better than the “bad players,” not the best or a cheat.

Quality and Role of News Sources

• Several complain that the WSJ front page has become ideological/clickbait and is no longer a concise business summary.
• Others contrast it with more data‑centric sources; some lament a general decline in mainstream media quality.

Study / Game Design Critiques

• Criticisms: small sample size, low stakes for students, restricted instruments (S&P and 30‑year futures), and cherry‑picked volatile days.
• Some see the game as marketing for the sponsoring firm and question its real‑world applicability.
• Others note experienced traders in the study did well, possibly because they remembered events or applied concepts like “buy the rumor, sell the news.”

Broader Reflections: Inequality & Long-Term Investing

• Commenters note that needing capital and risk tolerance means markets tend to favor the already‑rich.
• Long‑term trends (e.g., tech bubbles, Bitcoin, COVID) are seen as easier to reason about than single‑day reactions, but still hard to monetize without timing and capital.