Questions tagged [arima]
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36
questions
1
vote
1answer
138 views
Why is $Z_t$ uncorrelated with $X_{t-1}$ in $X_t=\theta X_{t-1}+Z_t$?
In a solution to the problem below, the teaching assistant solves it by calculating $\mathbb{E}[X_t^2]$ and ends up with also having to calculate $\mathbb{E}[X_{t-1}Z_t]$ after expanding the square. ...
0
votes
0answers
60 views
Do I use % return, log return or diff of prices to plot ACF?
I am reading a book on time series. To make a non-stationary series stationary, sometimes we need to difference the series. When it comes to finance, prices are non-stationary. Many authors fit ARMA ...
1
vote
0answers
32 views
Price Prediction Intervals from Forecasted Returns (ARIMA)
I have successfully fit an ARIMA model to a time series of the daily returns of power futures prices. The question I have is: How can I create a prediction interval for the prices? Or, alternatively, ...
0
votes
0answers
77 views
Forecasting returns and volatility using ARIMA-GARCH model in R
I am using rugarch package in R to forecast returns and volatility of a stock. I train an ARIMA (p ,d q) + GARCH(s, r) model on ...
0
votes
0answers
49 views
What is the Id in the ARIMA model in Notes on financial risk of Privault?
I hope this is the right place to ask this question. I am studying the time series from Privault's Notes on Financial Risks. In the ARIMA model part I can't understand what is "I_d", it is ...
2
votes
0answers
58 views
Electricity Futures Risk Premiums With ARIMA
I am attempting to model long-term electricity prices using today's futures prices. Unlike most futures, electricity is delivered over a period of time (usually a month), rather than at a point in ...
0
votes
0answers
27 views
ARMAX model with rolling window for predicting inflation
First of all, similar questions like mine are answered on this forum but I never quite saw an answer to this specific question. I'm trying to predict inflation by using an AR model with exogenous ...
5
votes
0answers
132 views
How to model financial HFT time-series data with multi scale autocorrelation
I work with tick level time-series univariate prices data. Tick level means that there are hundreds to thousands observations per second. The observations are timestamped, so one can use both wall ...
1
vote
0answers
62 views
Exploding forecast when increasing sample size in ARIMA in R/Python
I am fitting ARFIMA - eGARCH to time-series log returns in Python using R Rugarch package. The sample size is 2000, and I am doing 1-step ahead forecast. The following is the output
...
0
votes
0answers
37 views
Fitting a Spread into ARIMA AR(1) process
I'm a newbie to econometrics. I've simply ran a regression and have coefficient values of the variables. I'm running a regression for a crypto data, and I've gotten the Spread of the variables. To ...
1
vote
2answers
132 views
Exchange rate trend-stationarity
I am kinda new to time-series analysis, I want model CEE (EUR/HUF, EUR/PLN, EUR/CZK, EUR/CHF) exchange rates with ARIMA. I understand that according to Box-Jenkins modeling, I should first check if my ...
1
vote
0answers
117 views
Conditional and unconditional variance, autocovariance and autocorrelation of an ARMA process
Given an ARMA(1,1) process $x_t = a + bx_{t-1} + \varepsilon_t + \theta\varepsilon_{t-1}$, how can we
find the conditional variance, i.e. $Var_{t-1}(x_t)$,
find the unconditional variance, i.e. $Var(...
0
votes
0answers
76 views
Is non-linear correlation problematic in financial time series prediction?
Many traditional finance models assume linear relationships between variables and features. Aren't linear correlations/covariances unable to capture financial processes empirically since they actually ...
1
vote
1answer
155 views
What are some good models for stock price predictions?
For the fitting and forecasting of time-series data on stock price, the most frequent model I have heard of is ARIMA. ARIMA is actually conducting a regression of stock prices and residuals of stock ...
2
votes
0answers
39 views
The residuals of GARCH model reject Engle’s Test despite large parameters
I'm trying to build a model to predict the volatility for a financial asset with ARIMA-GARCH model. (I use log returns as data)
I fit my ARIMA model with AIC and I did Engle’s Test to ensure there is ...
0
votes
0answers
88 views
Fitting a non-stationary GARCH model
I'm very new to financial time series. I have a dataset containing the daily simple returns of the Dow Jones Industrial Average and I want to model a (univariate) GARCH model for the daily logreturns. ...
8
votes
2answers
1k views
Differencing vs Detrending financial time series
I'm quite newbie to time series analysis and I have to understand what's the difference between differencing time series (i.e considering $Y_t= X_t-X_{t-1}$) and detrending (using linear regression ...
1
vote
0answers
294 views
Combining SARIMA and GARCH model for prediction in python
I need to understand the concept of combining (S)ARIMA and (G)ARCH model for the predicting time-series data.
I understand that after fitting the arima model ...
2
votes
0answers
80 views
Problem with Hurst exponent estimation for ARFIMA models
guys.
I try to realize my ARFIMA model identification script in R. I try to find the best method for unbiased Hurst exponent estimation (fractional difference parameter could be found as Hurst - 0.5) ...
0
votes
1answer
3k views
MLE error in R: initial value in 'vmmin' is not finite
I am trying to fit an ARIMA(1,1)-GARCH(1,1) model. I changed the starting values a lot but still its returning the same error.
Below is my code which contains two functions ...
1
vote
2answers
235 views
Error distribution assumption in a simple ARIMA model
why in an ARIMA-GARCH structure I have to assume an error distribution to run the estimation while in a simple ARIMA model it is not required?
Thank you
1
vote
1answer
58 views
Can GARCH volatility simulations generally be applied to return-modelling models?
This may be a naive question, but I still hope some discussion can elucidate a (so far) totally nebulous point for me.
I've recently learned that GARCH models can give one simulations of ...
-1
votes
1answer
68 views
ARIMA vs ARIMA + GARCH [closed]
If an ARIMA model converges quickly, would using GARCH improve the forecast performance? By improve I mean provide longer time periods for forecasts. Basically trying to forecast returns.
0
votes
0answers
674 views
Interpreting ACF/PACF of return series
Researching a return series on some currency pairs I grabbed 2 years worth of daily data and got to work trying to fit an ARIMA/GARCH model to it.
Fitting the (log) return series:
...
1
vote
1answer
70 views
Are some stock prices not ARIMA(0,1,0) processes?
I am studying stock prices. Let Pt be price of stock at time t.
While Pt is non stationary, the return, rt=log(Pt/Pt-1) is stationary.
However, when I study on rt, I decide on an ARMA(0,1) without ...
2
votes
4answers
387 views
ARIMA model coefficients from discontinuous data series
Stock prices are not stationary processes during all week or all day. For example EURGBP has low variability at night in Europe but during working hours is changing much more dynamic because of market ...
3
votes
1answer
2k views
Please advice free Java library for classical time series forecasting
I've got an ARIMA model (with a GARCH model for variance estimation) and parameters estimated in Matlab for my set of data. Now I need to use this model in my Java based application for making ...
1
vote
0answers
142 views
ARIMA prediction for currencies
I was browsing TradingEconomics.com and I came across their forecast models which immediately captivated my interest. They describe them as "projected using an autoregressive integrated moving average ...
1
vote
0answers
110 views
x13 Arima analysis with negative values
I'm running x13 Arima analysis on a US GDP series to get the "trend" component.
...
34
votes
5answers
6k views
Why aren't econometric models used more in Quant Finance?
There is a big body of literature on econometric models like ARIMA, ARIMAX or VAR. Yet to the best of my knowledge practically nobody is making use of that in Quantitative Finance. Yes, there is a ...
2
votes
1answer
251 views
Automate selection of BIC-minimizing ARIMA(1,0,X) model
I want to estimate an ARIMA(1,0,X) model. The MA(X) in the model is selected to minimize BIC. I have the following code employing the function auto.arima from "...
1
vote
1answer
741 views
ARIMA Forecasting always converges?
I read an article about arima forecasting and i said that before we forecast arima model, its stationarity has to be checked.
If the model is stationary, it is clear that forecasting converges to ...
4
votes
1answer
753 views
rollapply with Arima model: testing for stability of coefficients
I am trying to fit an arima model on a rolling window using rollapply.My aim is to plot a graph of the evolution of the coefficient, plot the error and the standard deviation.
well i encountered the ...
2
votes
2answers
5k views
How to fit a SARIMA + GARCH in R?
I'd like to fit a non stationary time series using a SARIMA + GARCH model. I have not found any package that allow me to fit this model.
I'm using rugarch:
...
6
votes
4answers
3k views
Is there any way to easily estimate and forecast seasonal ARIMA-GARCH model in any software?
I use R to estimate a seasonal ARIMA(8,0,0)(5,0,1)[7] model for the seasonal differences of logs of daily electricity prices:
...
2
votes
1answer
169 views
What do I need to do with my data before fitting the ARIMA model?
I'm fitting a stock price time series data to ARIMA model and I have a question about the assumption.
Is it that ARIMA only applies to stationary data? The ACF and PACF of the data (and the logged ...
