TOKYO, July 27 Reuters From a rising yen to debt market derivatives, market signals reveal how investors are going for some cheap but failsafe options to make money on the off chance the Bank of Japan surprises them with a tweak to policy settings this week.

The trading pattern in the runup to the BOJ39;s twoday meeting, which ends on Friday, is familiar Investors have been betting all year the BOJ will finally relent on its stubborn ultraeasy monetary stance and adjust its yield curve control.

But this time, wary of repeated past disappointments, many investors are avoiding direct and potentially expensive bets such as shortselling Japanese government bonds JGBs, a trade often referred to as the widowmaker for the crushing losses it inevitably generated.

They have instead bought back the yen, and positioned through the bond options market for a spurt in volatility, giving themselves room to gain from a variety of outcomes.

At the same time, the rally in the weak yen and the apparent absence of shortselling of JGBs is giving the BOJ room to move without a wild reaction in markets.

Speculative positioning is relatively light, and this presents a good opportunity for the BOJ to take its next incremental move, said Jimmy Lim, chief investment officer at Singaporebased Modular Asset Management.

Lim thinks the odds of an adjustment to yield curve control YCC, which keeps shortterm yields negative and caps 10year yields at 0.5, are 60 to 40. He is thus positioned in…