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Table 22 Variables and the corresponding definition

From: A hybrid model for stock price prediction based on multi-view heterogeneous data

Variable

Definition

\(f_{t,m}\)

The occurrence frequency of \(word_m\) in \(news_t\)

\(F_m\)

The occurrence frequency of \(word_m\) in the news corpus

A

The number of times that word w and category c co-occur

B

The number of times that word w occurs without category c

C

The number of times that category c occurs without word w

D

The number of times that neither category c nor word w occurs

P(c)

The frequency of category \(c \in \{-1,1\}\) in news corpus

\(\xi _i\)

A slack variable

C

A penalty term controlling the cost to misclassification of samples

\(\alpha _{i}\)

A Lagrangian multiplier corresponding to sample \(x_i\)

\(k(x_{i},x_{j})\)

The kernel function

\(\gamma\)

A Gaussian kernel parameter

\(\beta _{m}\)

The weight of kernel \(k_{m}(x_{i},x_{j})\)

\(o_{t}\)

The first order differencing of a data series \(z_t\)

p

The autoregression order

d

The differencing order

q

The moving average order

\(\phi _{i}\)

The i-th autoregression parameter

\(\theta _{j}\)

The j-th moving average parameter

\(\epsilon _{t}\)

The error term at time t

\(r_t\)

Stock daily return on \(day_t\)

\(tv_t\)

Trading volume on \(day_t\)

\(tr_t\)

Turnover rate on \(day_t\)

\(mc_t\)

Market cap on \(day_t\)

\(md_t=(r_t, tv_t, tr_t, mc_t)\)

The market data including four market variable on \(day_t\)

\(md^{k}_t\)

The k-th market variable on \(day_t\)

\(max\{|md^k|\}\)

The maximum value of the k-th market variable

\(q_{\alpha }\)

The critical value of Nemenyi test

K

The number of involved algorithms

\(N_{stock}\)

The number of stocks

\(T_1\)

The news window

\(T_2\)

The market data window

\(w^{T_1}_{t,m}\)

The weight of \(word_m\) obtained from \(T_1\)-days of news

r(i)

The return obtained from the trading strategy on trading \(day_i\)

\(signal_i\in \{0,1\}\)

A dummy variable representing the corresponding strategy signal on trading \(day_i\)

\(\bar{r_{e}}\)

The average of daily excess returns during the simulation period

\(\sigma _{e}\)

Volatility of daily excess returns during the simulation period

\(r_{f}(i)\)

The risk-free rate of interest on the trading \(day_i\)

\(r_{i,j}\)

The daily return of stock j on trading \(day_i\)

\(signal_{i,j}\in \{0,1\}\)

The corresponding strategy signal of stock j on trading \(day_i\)