A book-to-bill ratio of less than 1 is usually interpreted as a signal that the market is shrinking since booking is below billing.

Booking on a three-month moving average in June was 106.4 billion yen (US$1.1 billion*), having declined 9.7 billion yen or 8.3% from the previous month. Billing in June was 100.1 billion yen, a sharp 40.7 billion yen or 28.7% decline from May

* Original figures are in Japanese yen. The exchange rate is roughly US$1=100 yen.

The sharp decline in billing in June should be viewed in perspective: it is a three-month moving average and the May figure was influenced by the spike in deliveries in March, the final month of the fiscal year. Now that March no longer gives an illusory boost, booking is continuing at a modest level, reflecting the vigorous market, according to a SEAJ spokesperson. In particular, assembly and test equipment keep on growing.

Related site:
Book-to-Bill Ratio (Express Report) (English in page 2)