public TreeSet<StockStatistic> computeCorrelation(StockTicker correlationForTicker, int period, CorrelationType correlationType) {
        log.debug("Finding most correlated stocks for: " + correlationForTicker);
        if (period != 10 && period != 30 && period != 60 && period != 90) {
            throw new IllegalArgumentException("Wrong period");
        }
        Objects.requireNonNull(correlationForTicker);
        Objects.requireNonNull(correlationType);

        step = 0;
        isComputing = true;

        Correlator correlator = getCorrelatorImpl(correlationType);
        TreeSet<StockStatistic> correlationTreeSet = new TreeSet<StockStatistic>();
        final EnumSet<StockTicker> tickersToScan = complementOf(EnumSet.of(correlationForTicker));
        final double[] sourceClosePrices = getClosePrices(getContent(correlationForTicker, period));

        ExecutorService executor = Executors.newFixedThreadPool(2);

        for (StockTicker ticker : tickersToScan) {
            executor.submit(() -> {
                double[] targetClosePrices = getClosePrices(getContent(ticker, period));
                double correlation = correlator.correlate(sourceClosePrices, targetClosePrices);
                StockStatistic statistic = new StockStatistic(correlation, ticker);
                correlationTreeSet.add(statistic);
                increaseStep();
            });
        }

        executor.shutdown();

        try {
            executor.awaitTermination(1, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        this.step = 0;
        this.isComputing = false;
        return correlationTreeSet;
    }