GLOBAL SEARCH

搜索课程、模块、题目与收藏题单

搜索在服务端完成,题目解析与答案不会进入搜索结果。登录后可搜索自己的收藏题单。

找到 30 个结果

中文题目
题目1764 · 统计

Selection Bias from Looking Only at Filled Orders

A desk studies how aggressiveness $X$ affects trade profitability $Y$, but $Y$ is observed only for orders that actually fill. Fill probability is higher when latent market demand $D$ is strong, and stronger demand also tends to improve profitability. Why can regressing observed

打开 →
题目1758 · 统计

Selection-on-Survivors Bias in Strategy Evaluation

A desk only records post-launch performance for strategies that first clear an internal backtest hurdle. Why does regressing realized performance on backtest score inside the launched set generally fail to recover the unconditional relationship?

打开 →
题目5829 · 金融与交易

In a market the per-trade adverse-selection cost to a dealer

In a market the per-trade adverse-selection cost to a dealer is alpha*delta, where alpha is the informed fraction and delta is the value gap. Noise traders are willing to pay at most a half-spread of 0.30 before they stop trading entirely. The value gap is delta = 1.0. Above what

打开 →
题目5792 · 金融与交易

Break-Even Width Against Adverse Selection

When a resting quote fills, with probability 0.30 it is an informed pick-off that moves 0.05 against the maker; with probability 0.70 it is noise flow with zero adverse move. Ignoring rebates, what minimum half-spread makes expected per-fill PnL exactly zero?

打开 →
题目5808 · 金融与交易

Net Edge After Adverse Selection

You capture a half-spread of 0.04 per share when filled. A fraction 0.35 of your fills come from informed traders, and on those fills the fair value moves 0.10 per share against you (uninformed fills have zero subsequent move). What is your expected net edge per fill, per share?

打开 →
题目5939 · 概率

Secretary Selection When Ties Are Possible

Three items arrive in uniformly random order. Their qualities are NOT all distinct: two of them have quality 2 (tied for best) and one has quality 1. After each item you observe its quality relative to those seen so far, reported as 'higher', 'tied', or 'lower' (so a tie is visib

打开 →
题目5371 · 金融与交易

Realized Spread And Information Cost 1

A buy trade occurs at 100.02 when the midpoint is 100. Five seconds later the midpoint is 100.03. What are the effective spread, realized spread, and adverse-selection component?

打开 →
题目5372 · 金融与交易

Realized Spread And Information Cost 2

A sell trade occurs at 49.96 when the midpoint is 50. Five seconds later the midpoint is 49.94. What are the effective spread, realized spread, and adverse-selection component?

打开 →
题目5451 · 金融与交易

Required Widening 1

A market maker wants net edge 0.018 per fill after adverse-selection loss. If expected loss is 0.007, rebate is 0.001, and current half-spread is 0.012, what half-spread is required and how much extra widening is needed?

打开 →
题目5835 · 金融与交易

Two venues route flow to your quotes. Venue A flow is 5% inf

Two venues route flow to your quotes. Venue A flow is 5% informed; Venue B flow is 40% informed. Both have the same value gap delta = 0.5, and informed flow costs you delta per fill while you earn half-spread s = 0.10 on all fills. You can only post on one venue. Compute expected

打开 →
题目5827 · 金融与交易

A dealer faces order flow where a fraction 0.4 of traders ar

A dealer faces order flow where a fraction 0.4 of traders are informed (always trade in the correct direction) and 0.6 are noise traders who buy or sell with equal probability. The true value is equally likely high or low, so informed traders buy half the time and sell half the t

打开 →
题目5830 · 金融与交易

A dealer has just observed a buy order and updated the poste

A dealer has just observed a buy order and updated the posterior probability that value is high to 0.70 (value high = 102, low = 98). A second buy order then arrives. In this model informed traders buy when value is high with probability 0.9 and when value is low with probability

打开 →
题目5836 · 金融与交易

A dealer quotes a single ask price A for a stock whose value

A dealer quotes a single ask price A for a stock whose value V is uniformly distributed on [40, 60]. An informed counterparty buys only when V > A (the quote is too cheap). Conditional on getting filled at ask A, what is the expected true value of the stock, and what does this im

打开 →
题目5833 · 金融与交易

A dealer quotes a two-sided market and earns the half-spread

A dealer quotes a two-sided market and earns the half-spread s on every fill. A fraction alpha = 0.15 of fills are informed and cost the dealer the full value gap delta = 0.8 (the dealer is on the wrong side for the entire move). The remaining fills are noise and the dealer keeps

打开 →
题目5832 · 金融与交易

A dealer's clientele is 20% informed and 80% noise on the cu

A dealer's clientele is 20% informed and 80% noise on the current trade. Informed traders, when present, always pick the profitable side; noise traders are random. The dealer has just been adversely picked off (filled on the wrong side). Going into the NEXT incoming order, the de

打开 →
题目4351 · 机器学习

Asymmetric Threshold Choice 1

Three candidate thresholds on the same classifier yield t=0.3 -> FP=18, FN=4; t=0.5 -> FP=9, FN=7; t=0.7 -> FP=4, FN=14. If one false negative costs 5 units and one false positive costs 1 unit(s), which threshold minimizes expected classification cost over this sample?

打开 →
题目4387 · 机器学习

Before Adding More Dimensions

Two hyperparameter settings differ in mean CV score by only 0.001, while the estimated standard error is 0.010. What is the first sensible interpretation?

打开 →
题目4390 · 机器学习

Before Blaming The Search

The current best setting sits at extreme values on both the learning-rate and regularization grids. What should your next search action be?

打开 →
题目4389 · 机器学习

Before Choosing Nested CV

A categorical encoder was fit once on all rows and then reused inside cross-validation. What is the immediate correction?

打开 →
题目4388 · 机器学习

Before Reporting Best Score

A time-series tuning run says a very short lookback window wins, but recent live performance has deteriorated sharply. What should you inspect first before widening the search?

打开 →
题目4386 · 机器学习

Before Tuning

Training AUC is very high but CV AUC is near chance. Before trying more hyperparameter values, what is the first diagnostic step?

打开 →
题目4334 · 机器学习

Before Using CNN

What is the first structural property you should verify before leaning on a CNN as your main architecture?

打开 →
题目5031 · 机器学习

BIC Improvement Threshold for an Extra Component 16

A mixture model with one extra component would add Delta k = 3 free parameters on a sample of size n = 100. Under BIC = -2 log L + k log n, what minimum log-likelihood improvement Delta log L is needed before the larger model is preferred?

打开 →